concepts of i.t

7/27/2019 concepts of I.T.

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Courses: Concepts of Information Technology (IT)

You can print this text-only version of this course for future reference.

If you wish to use the accessible version of our courses, which includes questions in text-only format,

click Text Only on the log on page, and then enter your user ID and password from the Accessibility LogOn page.

Lesson 1. Course Introduction

This series covers the objectives of the European Computer Driving Licence (ECDL) Version 4.0 exam.

You will learn about basic computer concepts and how to effectively use a computer. You will also learn

about the different types of software applications, including word processing, spreadsheet, database,

and presentation software.

In this course, you will learn the general concepts behind information technology (IT). This course will

provide you with an overview of computer hardware, memory, input and output devices, and storage

devices. You will also learn about the different types of software and how they are used to accomplish a

variety of tasks.

Finally, you will learn about networks, the Internet, the World Wide Web and how information

technology is used in everyday life.

This ECDL Foundation approved courseware product incorporates learning reinforcement exercises.These exercises are included to help the candidate in their training for the ECDL. The exercises included

in this courseware product are not ECDL certification tests and should not be construed in any way as

ECDL certification tests. For information about Authorised ECDL Test Centres in different National

Territories please refer to the ECDL Foundation website at www.ecdl.com.

The European Computer Driving Licence Foundation Ltd.

Lesson 2. Information Technology

Whether you have never used a computer before, or have some computer experience, this lesson willprovide you with some introductory information about computers and information technology.

After completing this lesson, you should be able to:

Define the terms hardware, software, and information technology (IT)


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Lately, nearly every issue of newsmagazines and every newspaper business section announces new

developments in information technology. Every day advertisements announce new upgrades and new

enhancements. Information technology changes so fast that today's "recent" becomes tomorrow's

"obsolete".

Information technology includes the design, development, installation and implementation of

computerized information systems and applications.

Central to information technology is the computer, which is a programmable electronic device, which

receives, manipulates, stores, and sends data. It requires a connection to electrical power and

instructions from a person using a software application or computer program.

The computer parts that you can see and touch are its hardware. Program and application instructions

and electronic data are its software.

The modern world can be thought of as an Information Society. In the past, the world's economy has

depended primarily on agriculture and manufacturing. Today, the global economy depends increasingly

on the creation and distribution of information.

This transformation is largely due to the invention of the computer, which allows people in remote

locations to quickly and easily exchange data.

The computer has led the world from the industrial age to the information age.

Early computers required their users to know advanced mathematics and cryptic coding languages.

Today, computers are so easy to use that little children can use them to learn and to play games.

Useful tools of the Information Society include software applications that enable you to work with

words, numbers, data, and images in electronic formats.

Word processing, spreadsheet, database, and presentation applications are the tools of today's

workplace.

Political leaders have discussed the need for an Information Superhighway, a global infrastructure that

would provide quick, abundant information to the general public.

With the advent of the Internet, the concept of an Information Superhighway has become a reality.

The Internet and its World Wide Web (WWW) of linked pages of information and electronic mail extend

the reach of computers beyond the home and workplace.

A computer connection to the Internet gives you access to a vast network of links and information that

resembles a universal brain.

This ECDL Foundation approved courseware product incorporates learning reinforcement exercises.

These exercises are included to help the candidate in their training for the ECDL. The exercises included





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In this lesson, you learnt that information technology includes the design, development, installation and

implementation of computerized information systems and applications.

You also learnt that a computer is a programmable electronic device, which has led the world from the

industrial age to the information age.

Finally, you learnt that computer hardware includes the computer parts that you can see and touch,

while software consists of program and application instructions and electronic data.

Lesson 3. Understanding Computer Types

As computers have evolved, they have become smaller and faster. They have become less expensive and

can handle ever-greater amounts of data in proportion to their size. Computers are usually classified

into three categories: mainframes, minicomputers, and microcomputers.


Identify various kinds of computers from mainframes to microcomputers

* Mainframes

Early computers were large mainframes that supported access by many users performing many tasks at

the same time.

Users at "dumb terminals" typed instructions transmitted by modems across telephone lines to the

mainframes. A dumb terminal does not have its own microprocessor and cannot run its own

applications. Its only function is to link users to a mainframe computer.

Because of their size, mainframes usually require a room of their own. They require a cool, dust-free

environment. Access to rooms housing mainframes is restricted to computer operators who monitor

computer activity.

Mainframes have evolved from their early beginnings and are still the largest, fastest, and most

expensive computers. These supercomputers are used to perform extensive mathematical calculations

and store vast amounts of data.


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* Minicomputers

Minicomputers are smaller, slower, and less expensive than mainframes. Minicomputers are used in

research laboratories and manufacturing plants where they provide specialized services. Over the years,

groups of minicomputers have replaced the single mainframe computers.

In many companies, people use a network of connected minicomputers or network computers and

microcomputers to perform data processing tasks.

Recently, technology has advanced to allow client/server computing to link a network of many client

computers with one or several server computers.

The server computers provide access to shared resources such as databases, and the client computers

provide the graphical user interface, a desktop with icons and windows.

* Microcomputers

Today, the most commonly used computers are microcomputers. Personal computers or desktop

computers are microcomputers.

Personal computers contain a microprocessor or microchip, and can stand alone to process data without

relying on a mainframe.

Personal computers usually have a diskette (floppy disk) drive, a CD drive, an internal hard disk drive,

memory, and their own disk operating system or DOS.

Microcomputers also include the smaller versatile laptop or notebook computers and personal digital

assistants (PDAs) or palmtop computers. Laptops and palmtop computers are small enough to travel

with you. Batteries can provide the energy required to run the computer.

Palmtops are often used as electronic calendars and address books. With a pen-like stylus, users can

write data to a small screen and perform activities on a palmtop computer. It's also possible to send and

receive e-mail messages using palmtops.

Palmtops continue to increase in popularity. As they become more popular, the speed and abilities of

the PDAs increase, while the costs decrease.

Originally, targeted toward the business community, the software available now makes them useful to

almost anyone from students, to doctors and nurses, to busy executives.

With the appropriate software, desktop and laptop computers can communicate with other computers

and access the World Wide Web.







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In this lesson, you learnt about the different kinds of computers that are available.

You now know that computers are usually classified into three categories: mainframes, minicomputers,

and microcomputers.

Finally, you learnt about the advantages and disadvantages of each computer type.

Lesson 4. Main Parts of a Personal Computer

A personal computer is comprised of several parts. Some of these parts are required, such as the central

processing unit and hard disk. Others are optional, such as a printer.


Identify the main parts of a personal computer

* Required Parts

The brains of the personal computer are in the system unit or console. Inside the system unit are the

central processing unit (CPU), the hard disk, the microprocessor chip, and memory.

The system unit is plugged into an electrical power source, usually through an intervening surge

suppressor.

Strictly speaking, the system unit is the computer; all of the objects attached to it by cables are

peripheral devices.

The visual display unit (VDU) or monitor is like a television screen.

You are looking at the visual display unit of your computer as you read these words. A cable connects

the VDU to the system unit.

The mouse, trackball, or similar device controls movement of a pointer or cursor on the visual display

unit.

When you move the mouse, the mouse pointer moves similarly on the VDU.


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You are already using the mouse as an input device as you click arrows to move from page to page in

this course.

Notice that the mouse pointer changes shape depending on where it is hovering. When it hovers over

most parts of the screen, it is an arrow.

When it hovers over parts of the screen that you can click to perform some action or move to another

page, the mouse pointer changes to a hand.

When the mouse pointer hovers over text that you can select to copy elsewhere, it becomes an I-beam.

The mouse has a left button that you press and release to click or select items displayed on the visual

display unit.

It also has a right button that you press and release to display a menu from which you can select

application-specific commands.

Some mice also have a roller that lets you scroll up and down within a window displayed on the VDU.

The keyboard is like a typewriter. The mouse and keyboard are the main means of your communicating

what you want the computer to do.

* Optional Parts

Now that you are familiar with the primary parts of the computer, let's look at some optional parts.

The printer lets you transfer electronic data to paper.

You can control whether the printer prints one or more pages, or an entire document or file.

If your system unit contains a sound card, you can listen to sounds through speakers or through a

headphone.

Though the system unit contains a hard disk, which stores data internally, you can also use removable

storage devices such as diskettes and external storage drives to store data files externally.

The system unit of most personal computers contains a diskette drive to receive diskettes. Because you

can both copy files from the diskette to your computer and copy files from the computer to a diskette,

the diskette drive and diskettes are used for both input and output.

An external storage drive can be attached to the system unit so that you can store vast amounts of data.

It can serve as a backup device to save copies of files on your computer.

The CD-ROM drive in the system unit of your personal computer lets you install software applications

from files on compact disks with read-only memory or CD-ROMs. You can also read and find information

on CD-ROMs.

A single CD can store over 600 megabytes of data, enough to contain an entire set of encyclopaedias.



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Topic 4.1 Exercises

* Exercise 1

Try identifying the parts of a computer.

Take a look at the computer you are using to take this course and identify the following components:

System unit Monitor Keyboard Diskette drive CD drive Mouse Printer Speakers

In this lesson, you learnt about the individual parts of a computer and how the parts are connected to

each other.You learnt that the brains of the personal computer are in the system unit, which contains several

required components, including the CPU, the hard disk, the microprocessor chip, and memory.

You also learnt that optional components, such as a printer and sound card, can be added to a personal

computer.

Lesson 5. Computer Performance


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There are several factors that impact a computer's performance, such as CPU speed, RAM size, and the

number of applications running.


Describe what the central processing unit does Distinguish between read-only memory and random-access memory Name units of measurement that are used to describe computer performance

Computers accept data and instructions (input), manipulate data (processing), store data (memory), and

present the results of processing (output). To perform these processes, computers use input devices,

processing devices and memory, and output devices.

* Central Processing UnitThe central processing unit (CPU) is the main processing device, receiving instructions and data from

input devices, applying operations on the input, and presenting results to output devices. It contains

electronic circuitry that performs arithmetic and logical comparisons and data-moving operations.

Inside the system unit, the motherboard holds the CPU and primary memory and connects to the hard

disk drive, diskette (floppy disk) drive and CD-ROM drive.

Expansion slots on the motherboard can hold a video card and sound card.

The video card converts electronic data to video display and provides support for video games.

The sound card enables the computer to transmit sounds.

* Computer Measurements

Today, relatively inexpensive desktop and laptop computers can perform more efficiently and less

expensively than early mainframe computers.

Generally, however, as computers increase in size, in CPU speed, and hard disk drive speed, their speed

and cost increases.

The speed of CPUs is measured in megahertz (mhz). Each megahertz is 1,000,000 cycles per second. The

CPUs of personal computers vary in speeds from 33 mhz to over 750 mhz. CPUs in large mainframes or

supercomputers can operate at speeds well over one gigahertz (1 billion cycles per second).

The speed of hard drives and diskette drives is measured in revolutions per minute (RPM). Current hard

drives offer speeds of 5400 or 7200 RPM.

Typically, diskette drives rotate at 300 RPM.

CD-ROM drive speeds are measured in X, each of which is about 150 kilobytes per second.


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A CD-ROM drive that reads and transfers data at the rate of 6 MB per second is rated at 40X. One that

does the same at 7.8 MB per second is rated at 52X.

Screen size of visual display units is measured diagonally across the screen. Most VDUs are 37.5 or 42.5

centimetres. Resolution, the ability of a visual display unit to show fine detail accurately, is measured in

pixels, also referred to as dots per inch (dpi). A 1,024 by 768 pixel setting is appropriate for a 42.5-CM

monitor.

Print quality is measured in dots per inch. Inkjet printers typically print 300360 dpi, and laser printers

print 3001000 dpi.

* Memory

Memory or storage contains the instructions and data being processed by the CPU. Data resides in

primary memory as needed.

When the computer is turned off, the information disappears from primary memory.

The memory in a CPU is random-access memory (RAM). The content of any memory location can be

read or changed independently of content in all other memory cells. RAM memory chips store programs

and data when a computer is running.

The more RAM a computer has, the faster it can work and the more software programs you can run

simultaneously. Applications that deal with very large files, such as photo-editing and video-editing,

benefit greatly from more RAM.

In addition, having multiple applications open at a time can slow down computer performance.

Therefore, even if you aren't working with large applications, you can still benefit from more RAM.

The other main type of primary memory is read-only memory (ROM). ROM is memory that stores a fixed

set of data permanently.

This data can be read but not changed.

Computer manufacturers use ROM chips for permanent storage of frequently used programs in the

computer's main memory.

Information on a computer is stored as binary digits 1 and 0. Each 1 or 0 comprises one bit of

information. An eight-bit group, also referred to as one byte, can store a single character.

For example, the letter A is one byte of information. The word "dog" requires 3 bytes. A word processing

file of 50 pages of text would typically require around 200,000 bytes.

As the amount of data increases, larger units of measurement become necessary. The table shown here

describes the most commonly used units of data measurement in the computer industry.

Unit Abbreviation Size Typical Use


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bit b 1 binary digit To hold either a 1 or 0

byte B 8 bits To hold a keyboard character

kilobyte KB 1024 bytes To measure files

megabyte MB 1024 KB To measure folders or directories

gigabyte GB 1024 MB To measure hard drives

terabyte TB 1024 GB To measure large databases

RAM in a desktop computer is measured in megabytes (MB). Typical RAM is 32 MB, 64 MB, or 128 MB.

Hard disk capacity in a personal computer should be at least 300 MB and can be higher than 20

gigabytes (GB).







In this lesson, you learnt about some of the factors that impact a computer's performance and how

computer performance is measured. You now know that CPU speed, RAM size, and the number of

applications running affect a computer's speed.

You also learnt about the different types of computer memory RAM (random-access memory) and

ROM (read-only memory) and how to distinguish between them.

Finally, you learnt how computer memory is measured, from bits to terabytes.


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Lesson 6. Input and Output

Input devices are your means of telling the computer what to do. Output devices accept electrical

signals from the CPU and convert them to make data available for use.


Identify computer input and output devices

* Input Devices

The basic input devices of a computer are the keyboard and mouse, but there are many other

alternative input devices available.

Let's take a look at some of these.

Digital cameras, microphones, and speech recognition units are also considered input devices. Digital

cameras transmit images to the computer. Microphones and speech recognition units pick up sounds so

that the computer can transform audible words into electronic data.

Scanners let you record image files from photographs and drawings. Scanners with optical character

recognition (OCR) convert textual information from images to text.

Barcode readers are able to scan information from barcodes as electronic data. Barcodes identify books

in libraries and products in stores.

* Output Devices

The most common output device is the visual display unit (VDU), also called a monitor or screen.

Current screens display the graphical user interfaces of various software programs and animated

imagery.

Older visual display units displayed only characters.

Another common output device is the printer. Relatively inexpensive inkjet printers can print in black or

many colours. Laser printers use toner to print black characters and images.

In addition to printers, there are plotters. Plotters are output devices that draw images on paper using a

pen, which allows them to create very precise drawings.

Other output devices include speakers and headphones for transmitting sounds from the computer.

Speakers allow a group of people to listen to the sounds, while headphones will let you listen to the

sounds privately.

* Input and Output

Touchscreens are capable of both receiving and displaying data. They display data just like a monitor.

The difference is that you can touch areas on the monitor instead of pointing and clicking with your

mouse.

Touchscreens are being used more frequently in sales, medical, and gaming equipment because of their


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ease of use.

A modem (modulator/demodulator) is an electronic device for converting data from a computer to

audible signals suitable for transmission over telephone lines, and converting audible signals to

computer data. It can be either a peripheral device or be embedded in the system unit. Because a

modem both receives and sends, it is technically both an output and input device.







In this lesson, you learnt about the various input and output devices. You now know that input devices

let you tell the computer what to do and that output devices make data and information available to

you.

You also learnt that the keyboard and mouse are the most common input devices and that the monitor

is the most common output device.

Finally, you learnt that some devices, such as touchscreens, are used for both input and output.

Lesson 7. Computer Storage Devices

Computers can use a variety of storage devices, including diskettes, Zip disks, data cartridges, CDs, and

internal and external hard disks. While these devices are similar in some ways, all differ in terms of

speed, cost, and capacity.


Describe the main types of storage devices Explain the purpose of formatting a disk

The internal hard disk provides storage for all software applications and data, whether they are in use or

not. More hard disk space means you can install more software and store more documents. Faster hard

disk drives improve program load times and overall computer performance.

The diskette drive built into the system unit accepts a diskette, which you can use to copy data from and


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to your computer.

Diskettes are the least expensive, slowest, and smallest of the storage devices. Newer, faster, higher-

capacity storage devices cost more than older, slower, lower-capacity devices.

External hard disks offer a combination of features found in internal hard disks and diskettes. External

disk drives offer similar storage capacity to internal drives, but also offer the portability of diskettes.

While they are quite a bit more expensive than diskettes, they are less expensive and easier to install

than internal hard disks.

A Zip disk requires a peripheral Zip drive to copy the files to the Zip disk. Zip disks can store more

information than diskettes, but they are also much more expensive.

A peripheral tape drive can make a backup copy of the contents of a hard drive to tape in a data

cartridge. Data cartridges are similar to Zip disks with regard to storage capacity and price.

Other kinds of storage devices let you copy files to a compact disc (CD). A CD can store more information

than Zip disks and data cartridges and are considerably less expensive.

Before disks can be used, they must be formatted. Formatting a disk writes information needed to keep

track of where files and folders will be located on the disk based on the operating system.

It's important to note that formatting a disk erases any information, files, and folders stored on the disk.







In this lesson, you learnt about the different types of storage devices. You now know that storage

devices include diskettes, Zip disks, data cartridges, CDs, and internal and external hard disks.

You also learnt how these devices differ in terms of speed, cost, and capacity.

Finally, you learnt that it is important to format a disk so that files and folders can be saved in the

appropriate place on the disks.

Lesson 8. Software

Software includes applications or programs of instructions that the computer can read.


Distinguish between operating system and applications software


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Understand the reasons for software versions

Anything you can do with words, numbers, and other forms of data, you can do with a computer.

But all of the computer hardware and storage are useless until they are put to work by instructions insoftware.

Programs can be as simple as several lines of code, or as complex as applications that perform a variety

of calculations, word processing, and database tasks.

Software applications are collections of programs that can assist you in performing all sorts of tasks.

These include word processing, spreadsheets, databases, and presentations. Internet applications allow

you to send and receive e-mail and provide interfaces to the Internet's World Wide Web.

The operating system (OS) is the most important software in the computer and is usually alreadyinstalled when you buy the computer. The OS serves as an intermediary between the hardware and

applications software. It lets you communicate with the computer.

* Software Versions

Software technologies are ever evolving. Software versions allow developers and companies to improve

software and fix bugs while having a working copy available to the public.

For those developing software, versions allow them to make changes without overwriting existing code.


These exercises are included to help the candidate in their training for the ECDL. The exercises includedin this courseware product are not ECDL certification tests and should not be construed in any way as




In this lesson, you learnt about the differences between operating systems and applications.

You also learnt that the operating system (OS) is the most important software in the computer and

serves as an intermediary between the hardware and applications software.

Finally, you learnt that software versions allow programs to be improved, while having a working copy

available to the public.

Lesson 9. Types of Software


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In addition to operating systems, there is a variety of useful software available today, including word

processing, spreadsheet, database, Web browsing, desktop publishing, and accounting applications.


Name some common operating systems List some common software applications Understand the term Graphical User Interface (GUI)

* Operating Systems

The operating system (OS) is the most important software in the computer. Among the most popular

operating systems currently used on PCs are Macintosh, Microsoft Windows, and Linux. When you buy

software, check to make sure that it will run on your computer's operating system.

Macintosh and Windows operating systems are each owned by a separate company. Because the Linux

operating system is not owned by a single company or organisation, there are several variations of

Linux.

This course describes how to meet European Computer Driving Licence Version 4.0 objectives using

Windows operating system.

The ECDL test can be taken with any operating system, and although this course demonstrates a specific

operating system, the procedures it teaches can be applied to other operating systems as well.

* Application TypesSoftware applications can assist you in performing sets of tasks from word processing and spreadsheets,

to databases and presentations. They also help you send and receive e-mail. Internet browsers such as

Microsoft Internet Explorer and Netscape Navigator provide interfaces to the Internet's World Wide

Web.

Personal computers are more often used for word processing than for computing data.

You can use a word-processing application to write a letter, report, or an entire book. Word-processing

programs let you edit as you work and automatically check your spelling.

Popular word processing applications are Corel WordPerfect and Microsoft Word.

You can use a spreadsheet application to list data in rows and columns that intersect to form box-like

cells. You can perform calculations on the data and convert the data to a variety of charts.

Bookkeepers and accountants work with spreadsheets. So do people who budget their income and

record their expenses by categories.

In addition to spreadsheet software, there is accounting software that allows you to more easily track


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your income and record expenses. It can be used to simply plan a budget or conduct sophisticated

financial planning.

Large corporations use accounting software for a variety of functions, including payroll, budgeting, and

investing to name a few.

If you want to store and retrieve data as records having various searchable fields, you can build and

manage databases with an application such as Microsoft Access.

Databases are used by researchers and by hobbyists who, for example, want to record information

about their collections, or about their family history and genealogy.

You can create electronic slide shows that combine your data with a variety of interest-grabbing

graphical enhancements.

A presentation program such as Microsoft PowerPoint helps you develop overhead transparencies or

slides that you can present to groups of people.

Desktop publishing applications such as QuarkXPress and PageMaker allow you to create professional-

quality printed materials such as brochures, reports and magazines.

You can create informative and entertaining Web sites using multimedia applications such as FrontPage

and Dreamweaver. Other multimedia programs, such as Flash, help you make your Web pages more

visually exciting by adding animation.

Internet browsing programs let you find Web sites and display Web pages on the World Wide Web.

Currently popular browsers are Netscape Navigator and Microsoft Internet Explorer.

E-mail (electronic mail) has revolutionized both business and personal communication. An e-mail

message can be sent to the other side of the world in a matter of seconds (without the price of a stamp).

E-mail programs include Microsoft Outlook and a large variety of free programs offered by Internet

service providers and some Web sites.

* The GUI

Early operating systems were cumbersome to use, requiring exact syntax for commands and their

parameters. Some employed character-cell interfaces which required the user to enter each character of

a command in the correct location in a grid.

Today's operating systems present a screen displaying icons on a desktop. This is called a graphical user

interface (GUI). You can double-click the mouse on an icon to start a program or application.

Let's examine the various components of a GUI.

Within an application, you can open menus and choose various submenus to perform different options

and tasks.

Dialog boxes present lists and buttons that you can click to instruct the computer about what you want


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it to do.

The GUI lets you have several applications open at once so that you can do several things at one time.

While a document is being printed, you can adjust data on a spreadsheet. You can easily copy selected

words or paragraphs of text from one document to another.







In this lesson, you learnt about different operating systems. You now know that some of the most

popular operating systems include Macintosh, Microsoft Windows, and Linux.

You also learnt about different components of the GUI, including icons, menus, and dialog boxes.

Finally, you learnt about the different types of software applications that can be used for creating word-

processing documents, spreadsheets, databases, and presentations.

Lesson 10. Systems Development

Many computer applications are very complex and take a great deal of time to develop. The

development of these applications requires a systematic approach.


Describe how computer-based systems are developed

During the analysis phase, systems analysts research what needs to happen to solve a problem or make

processes more efficient.

They often write a system requirements document, and work with project leaders to schedule tasks and

allocate the people and time needed to complete parts of the process.

During the design step, the team details the system requirements in terms of how they relate to the

business and features of the application.

The team will also outline the process, identify how the application screen should appear, and create


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other documents, including pseudocode, which is an outline of the code that will be developed later.

The necessary new computer programs are developed during the programming phase. Programmers

study system requirements and then develop computer programs and applications.

They produce prototypes or representative examples of what their applications can do.

Before a computer system is put into production, it must go through a testing phase. Quality assurance

staff test the output of the program and programmers fix detected errors.

When managers and quality assurance staff agree that the system is ready, it can go into production.







In this lesson, you learnt that software development requires a systematic approach.

You also learnt that there are specific phases involved in developing software analysis, design,

programming, and testing.

Lesson 11. Networks

Whether you are using a computer at work or at home, its capabilities are increased by attachment to anetwork. At home, for example, a network can link two or more computers to a shared printer.


Define the terms local area network, wide area network, and client/server List advantages of working on a network Describe what the World Wide Web is and distinguish it from the Internet Explain how the telephone is used in network computing

* LANs and WANs

There are two kinds of networks: local area networks (LANs) and wide area networks (WANs).

Some advantages of networks include shared access to files and software applications located on a

network drive. A network also offers access to peripheral devices, such as printers, so that several

employees can share the same device.


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In addition, a network lets employees copy files from their hard drives to a network drive that gets

backed up to a large server, to tape, or to another medium every night.

Now, let's take a closer look at LANs and WANs.

A local area network (LAN) links computers to other computers and to peripherals by a wire-based

cabling scheme. It enables sharing of resources. A LAN is user-owned and does not run over leased lines.

A hub serves as the common wiring point, enabling data to be sent from one computer to another over

the network.

A wide area network (WAN) covers a larger geographical area than a LAN and relies on

telecommunications links that are leased from providers. Examples of WANs include the Public Switched

Data Network (PSDN), Public Switched Telephone Network (PSTN), and Integrated Services Digital

Network (ISDN).

In a client/server architecture, the network includes PCs that either act as a server or a client.

Servers are the most powerful PCs that are responsible for managing network resources. Clients are PCs

that act as workstations for the users and include user applications. Clients depend on network servers

to access network resources, such as printer and file systems.

* The Internet

The Internet is a network of networks. It supports the World Wide Web (or Web), the interconnected

set of universal resource locators (URLs) or addresses for Web sites, and their hyperlinked pages. You

can go to a Web page by typing a URL in the address area of the browser screen, or go from one Web

page to another by clicking a hyperlink, an underlined word or phrase often of another colour, that

displays another Web page.

The World Wide Web and Internet are two different things. The Internet is a communications network

of networks, routers, and computers across the world that enables people to communicate by means of

electronic mail and publish information by means of Web sites.

The World Wide Web, is just one way of accessing information over the Internet.

Unlike the Web, the Internet is used for e-mail, instant messaging, and other services.

Search engines available at sites such as AltaVista, Lycos, and Yahoo! help you find what you're looking

for on the Web. To use a search engine, you type a word or phrase for which you are looking and click a

Search button.

The search engine conducts the search and displays a list of portions of the pages that contain the word

or phrase. Each entry on the list provides a hyperlink to the Web site. A hyperlink is usually shown as

blue, underlined text. Clicking a hyperlink in the list displays the page containing the search term.

The Internet also supports a means of exchanging files between computers known as File Transfer

Protocol (FTP), typed conversations among people known as Internet Relay Chat (IRC), and e-mail. .


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E-mail is the most widely used Internet application. To send and receive e-mail, your computer must be

connected to a modem. Your computer must also have an e-mail program such as Microsoft Outlook

installed on it, or it must have access to an e-mail program on a network. Some Web sites offer free e-

mail programs that you can use.

Though not as immediate as the two-way interaction of telephone calls, e-mail exchanges can be saved

and printed.

This way, conversations can be documented. Many of the interactions that businesses used to conduct

by mail or telephone are now conducted through e-mail.

* Intranets and Extranets

An intranet is actually an Internet that belongs to a specific business or organization. Unlike the Internet,

an intranet is only available to employees, members, or other authorized internal users.

An extranet is an intranet that is available to outside users in addition to internal users of the business

or organization. Extranets are being utilized more frequently to allow business partners to access each

other's information.

* Telephone Networks in Computing

The PSDN and PSTN are the collection of interconnected systems operated by various telephone

companies and utilities around the world.

They are used for transmission of voice, fax images, telex data, and other low-speed data.

The ISDN is a network capable of carrying several types of service: voice, digital network services, and

video. ISDN communications offer higher transmission speeds than PSDNs and PSTNs do.

ADSL (Asymmetric Digital Subscriber Line) is similar to ISDN in that it operates over telephone lines.

However, ADSL offers higher speeds than ISDN.

To extend the reach of your personal computer to the Internet and its World Wide Web and electronic

mail services, you must have a modem connection between the computer and a telephone jack.

A modem is necessary because of the difference in how analogue and digital signals are presented.

Analogue signals transfer data in a continuous format, while digital signals transfer data in separate

intervals and the data is stored in bits that contain either a value of 1 or 0.

These two types of signals can communicate because the modem translates the digital signals from the

computer to analogue signals that a telephone uses, and vice versa.

Modem speed is measured in baud rates. The higher the baud rate, the faster the translation of digital

signals. Actual data speeds will vary, depending on line conditions.

The telephone jack connects to a telephone line so that the PC can communicate with an Internet

service provider (ISP). When you connect to an ISP, you are connected to its computer system, which is

connected to the Internet. Supporting the Internet is a vast collection of server computers, telephone


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lines, routers, fibre optic lines, and communications satellites.

Network connections are supported by hubs, bridges, and gateways. Hubs link networks together so

that nodes within them can communicate with one another.

Bridges connect hubs together.

Gateways translate messages so that they can be used by various types of networks such as Apple

networks and PC networks.







In this lesson, you learnt about local area networks and wide area networks.

You also learnt about the World Wide Web and how it differs from the Internet. You now know that the

Web is part of the Internet, but not synonymous with it.

Next, you learnt about intranets and extranets. You now know that an intranet is available to internal

users of a business or organisation and an extranet is available to outside users in addition to internal

users.

Finally, you learnt about the different types of telephone connections used to access the Internet

PSDN, PSTN, ISDN, and ADSL.

Lesson 12. The Electronic World

Technically, any device that contains a microchip can be considered a computer. You may have dozens

of computers in your house right now. Anything from a television to a microwave oven to a musical

greeting card may be considered a computer.


List several ways computers are used at home, at work, and in the community

* Businesses

Computers are an important part of most businesses. From payroll systems used by small businesses to


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sophisticated business administration systems, most businesses use computers to conduct day-to-day

functions.

Many businesses, such as airlines and insurance companies rely on computers to process almost all of

their business transactions.

Let's take a look at how some businesses use computers today.

Before you even enter the door to your place of work, you may need to scan data on an identification

card or badge across a reading device.

A computer uses that data to authorise your entry and record that you entered the building at a certain

time.

Some factories use computers to guide robots in performing repetitive, dangerous, or very exacting

tasks.

When you buy things at a grocery store or department store, the person at the cash register or point-of-

sale (POS) device uses a device to read the barcode on the items. A network-connected computer

supports this activity.

The computer assigns the appropriate price to the item, sums the prices of items bought, adds tax,

calculates the total, and records payment. It also updates inventory data for the items purchased.

Businesses are striving to increase sales through electronic commerce, or e-commerce for short. Any

business transaction made via the Internet can be considered e-commerce.

Convenience is the biggest advantage to shopping online. You can shop when it's convenient for you

24 hours a day. You also have a wide variety of products from which to choose. A disadvantage is that

you don't get to actually touch the products you are purchasing.

It's important to understand the site's return policy. Even if you are able to return items, it may not

always be convenient. If the online site has a store near you, sometimes you can return the item to the

store. If not, you will need to return the product via the mail.

You should also keep in mind that when you purchase something online, you have to provide the site

with personal demographic and financial information and there is always the risk of encountering a less

than secure Web site and your information may be compromised.

If you pay for the items by credit card, a computer network connects data read from your card to data

about your bank account before authorising your purchase.

Automatic Teller Machines (ATMs) are computers that allow you access to your bank account without

the assistance of a bank teller. If you automatically deposit your pay cheque into your account, a

computer network handles the transaction between your employer and the bank.

Most banks today offer some sort of online banking services. These services let you manage your

finances and accounts online instead having to go to a banking office.

Features of online banking include opening and closing accounts, viewing account balances, reconciling

accounts, transferring funds, and paying bills.


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Smart cards are plastic cards containing a microprocessor so that you can add money value to them and

use them in place of currency in vending machines, photocopiers, and pay telephones. Microchips in the

card readers add, deduct, and transfer the money to the appropriate account.

* Telecommuting

The World Wide Web has made it possible for some people to log into their employer's network and

work from home.

This is a win-win situation, as the employee can avoid the daily hassle of getting to and from the office

and the employer can avoid the expense of maintaining office facilities for that employee. Other

advantages include reduced stress and flexible work schedules, all of which lead to an increase in

productivity and decrease in employee turnover.

While telecommuting is beneficial to the employee and employer, there are some disadvantages to

working from home. This includes a lack of human contact and less of an emphasis on teamwork.

* Government

Computers help governments handle many large-scale repetitive tasks, such as processing entitlement

checks, electronic voting, tax returns, or census forms.

Computers can never completely replace human labor, as some tasks simply aren't suitable for

machines. Computers can process tax returns and census forms, but they can't sit down with a taxpayer

and perform an audit, or manually take a census report from someone who didn't mail in a form.

Several countries have implemented some form of electronic voting. While manual, or paper, ballots

haven't been completely eliminated in most countries, using some sort of electronic voting technique

allows for a quicker and more accurate accounting of election results.

* Hospitals

Networked computers enable doctors, nurses, and other health professionals to see and update

patients' medical records which are kept in a database for easy access. Computers can also help doctors

perform complex procedures such as laser surgery and endoscopy.

Computers can also assist in the coordination of ambulances. Computer systems help to track the exact

location of ambulances and allow dispatchers to send the closest available ambulance to an emergency.

Computers free people to do what only they can do best, make complex decisions and provide loving

care.

* Schools

Schools can use computers to provide multimedia instruction and tutorials to students, or to e-mail

homework to their teachers. Teachers can use computers to calculate grades for report cards, and

administrators can use them to store student records.

Students can use computers to register for classes, access class timetables, and even complete

homework over the Internet. Computer-based training and distance learning allow students to take

classes online, without ever having to leave their houses.


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* Work and Play

With appropriate software installed on your PC, you can use it to help you manage your family's

household finances and even support your hobbies.

If your hobby is genealogy, for example, you can use your PC to search for information about your family

on the Web.







Topic 12.1 Exercises

* Exercise 1

Try looking around your home or office for the presence of computers. Notice how prevalent computers

and electronic devices are in modern life.

Here are a few examples of the computerized devices you might see:

Personal computers Audio/video equipment Calculators Electronic telephones Vending machines Any electronic devices that you may use in your job

In this lesson, you learnt how computers are a part of everyday life. You now know that computers can

be found everywhere in your home, at work, and in your community, and that, technically, they can be

any device that contains a microchip.

You also learnt about telecommuting, which allows employees to log into their employer's network and

work from home.


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Lesson 13. Health, Safety, and Environment

Computers can be helpful when used for constructive purposes, but can cause damage and be damaged

when they are not used correctly. There are, however, some things you can do to protect yourself, your

computer, and the environment.


List several ways to adjust your computer environment to prevent personal injuries Describe precautions to follow to prevent damage to a computer List ways to use a computer in an environmentally-sound manner

* Protecting Yourself

To protect your eyes from VDU glare, follow these guidelines:

Protect your vision by briefly focusing on an object at least six metres away from the monitorevery ten minutes or so.

Reduce the brightness of the VDU. Position the VDU at least an arm's length from your face. Position the VDU so that you can see the top third of the screen without having to tilt your head

up or down.

Avoid light shining directly into your eyes or onto the VDU. Use a monitor filter to reduce the amount of glare and reflection.

Eliminate excessive neck turning and the back and forth refocusing of the eyes between page and

screen.

Use a copyholder when you type from pages and books.

Protect your wrists from repetitive strain injury (RSI) or carpal tunnel syndrome by taking breaks from

long sessions of typing at the keyboard. Use wrist-supporting pads for your hands. Many mouse mats

now come with padding that will help your hand remain in a comfortable position. Protect your arms

and wrists by raising or lowering the keyboard so your forearms are parallel to the floor.

Over time, using bad posture at a computer can cause back problems.

Protect your back, arms, and legs by sitting upright in a chair that has arm rests, provides lower- and

mid-back support, and lets you sit with thighs parallel to the floor and feet resting on the floor.


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If necessary, use a footrest.

Make sure your work area is well-ventilated. Computers can generate a lot of heat that good ventilation

will help dissipate. Fresh air is good for users, too it will keep your mind sharp and prevent headaches

and fatigue.

Finally, be sure to take frequent breaks away from the computer. Protect your mental and emotional

health by realizing that people exist outside of and away from your computer. There is more to life than

information!

* Protecting Your Computer and Data

Plug your computer and all peripherals into a surge suppressor power strip rather than directly into

electrical outlets.

This will prevent your power outlets from being overloaded and will protect your valuable computer

equipment from damage due to power fluctuations or electrical storms.

There are many cables associated with a computer, some of which carry high voltage. Be sure to secure

your cables so they cannot be tripped over or crimped to the point of causing an electrical short. Think

safety!

Protect your software and data from corruption by viruses. Install anti-virus software and keep it up-to-

date by applying anti-virus updates. Do not open any attachments to e-mail messages until after your

virus-detecting software has verified that they are virus free.

When you are assembling your PC, attach all of its peripherals to the system unit before plugging the

computer into the surge suppressor.

Then turn on the current by using the switch on the surge suppressor.

Though a surge suppressor can protect your computer and stored data from being damaged by electrical

storms, you can lose some data if electrical power is cut by storm or accident while you are working in a

file. To prevent this loss from being severe, save your data every five minutes or so while you are

working in a file.

Back up your important data regularly. If you do not create and update many files, you can back up data

on diskettes.

Otherwise, use a Zip drive or similar high-volume-storage device to back up your entire hard drive

regularly.

When you are finished using the computer, first close all files you were using. Next, exit from all

programs and shut down the operating system. If your PC uses the Windows XP operating system, open

the Start menu, choose Turn Off Computer from the menu, and then choose Turn Off. Finally, turn off

any peripheral devices that are on, and then turn off the system unit.


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Try not to spill liquids or food on your keyboard. If you do spill something, turn off the computer, dry it

off, and clean the surface with a paper towel.

It is also helpful to turn the keyboard upside down to drain the liquid until it is dried out.

If your VDU screen shows finger smudges and dust, clean it by spraying window-cleaning solution on a

paper towel and then wiping the VDU screen with the paper towel.

* Protecting the Environment

You can do your part to protect the environment by

Recycling printed outputs, toner cartridges, and other computer components whenever possible Using a monitor that consumes less power while the computer is inactive Viewing electronic documents instead of printing them







In this lesson, you learnt about computer-related injuries and how to protect yourself from them.

You also learnt that many factors can adversely affect your computer and data. You now know some

ways to protect your computer from these dangers.

Finally, you learnt how to use your computer in an environmentally-sound manner, including recycling

outputs and viewing documents online.

Lesson 14. Security

As computer technology advances, so do the threats to your computer systems and data. It's vital to

protect the data on your personal computer from damage caused by computer viruses and


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unscrupulous individuals.


List several ways to protect data from being corrupted, stolen, or destroyed

* Information Security

Information security refers to the manner in which a business or organisation protects the information

on its computers and networks. Information security also includes protecting network and computer

hardware.

The first step an organisation can take to secure its information systems is to develop a security policy.

The policy should define the following:

Who has access to specific areas of the network and specific pieces of information How sensitive data is handled How security incidents are reported How staff members are educated about security and their responsibilities Who will manage the security policy

Determining who has access to your system is a very important step. User IDs should be assigned based

on specific access. The User ID tells the system who is at the computer and the specific access rights of

that user.

Access rights are important because they determine what information the user can access and their

rights to view and modify that information. For example, the user may have read access to a file, but not

write access. This means that the user can read the file, but cannot make changes to it or delete it.

While the User ID tells the computer what the user can access, passwords ensure the user is who he

says he is.

A security policy should require employees to enter a User ID and password before accessing the

system. It's also important that users keep passwords secret. Passwords should be easy for the user toremember, but hard for someone else to guess.

If you are going to be away from your PC and there is a possibility of others trying to use it without your

permission, shut it down. If your PC is a laptop, keep it in a secure place. When travelling with a laptop,

carry it with you.


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Laptops are favourites among computer thieves. If your laptop is stolen, not only will confidential

information be compromised, but you could possibly lose files and other information that is not

available elsewhere. Additionally, any personal information about yourself or coworkers could be

compromised.

PDAs often contain the same type of information as a laptop. Therefore, a stolen PDA causes the same

problems related to confidential information and loss of information as a stolen laptop.

Today's cellular phones allow you to store numerous names and numbers. If your cellular phone is

stolen, the names and numbers of friends and family are compromised. In addition, the thief can use

your cellular phone to make expensive long-distance phone calls. For that reason, it is very important to

report it stolen as soon as you notice it is missing.

* Computer Viruses

The Internet has not only been a way to quickly circulate helpful information, but it has also been a

quick way for vandals to intrude into your computer, destroy files, and overload Internet server

computers with junk messages. The main weapons used by these vandals are computer viruses.

A virus is a program that can "infect" other software by inserting itself in files and causing them to work

in unpredictable and often destructive ways. It can corrupt and destroy other files on your computer.

Defend your computer against such intrusions by installing an antivirus application and updating it with

data to detect new viruses that appear. Scan regularly all files on your computer's hard drive with the

antivirus application. In addition, you should scan all downloaded files and any e-mail attachments.

Using this scanning software will greatly decrease your risk of being infected by a virus. However, new

viruses are developed all the time and one limitation of scanning software is that it doesn't update itself

unless you tell it to. Therefore, you must to make sure your scanning software is updated on a regular

basis.

One very important thing you can do to protect yourself is to never open an attachment that is

contained in an unrecognised or unexpected e-mail.

If your computer should become infected with a virus, you can sometimes use the scanning software to

"disinfect" the damaged files, removing the virus and preventing it from spreading further.

However, if disinfecting the files does not fix the problem, you may need to remove all files and

software, and reload everything from the program installation CD-ROMs and from your backup media

for data.








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* Exercise 1

Try creating your own password. Here are some things to consider when choosing an effective

password:

Choose a password that you can easily remember Choose a password that others cannot easily guess If possible, use a combination of letters and numbers Avoid using your name or User ID Avoid using birth dates, licence plate numbers, telephone numbers, or any purely numeric

password

In this lesson, you learnt about information security. You now know that information security refers to

both the protection of information and computer hardware.

You also learnt the importance of controlling who has access to a network or computer through the use

of User IDs and appropriate passwords.

Lesson 15. Copyright and the Law

When initially accessing software, you should be aware of the legality of using a program or application.

Many computer applications and programs are copyrighted to protect them from being copied and

resold without permission.


Explain the differences among copyrighted software, shareware, and freeware Describe the purposes of data privacy and protection laws

If you use software at work, your company has probably purchased licences to use a specified number of

copies of various applications on its network client computers. These end-user licenses are one way that

your company complies with copyright regulations.

If you purchase software for personal use or download software from the Internet, you are responsible


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for reading, understanding, and complying with that company's copyright information.

Once you have acquired the software, you'll need to have the product ID number before it can be

installed. If you purchased hard copies of the software, this information will usually be printed on the

product documentation or on the CD you'll use to install it. If you downloaded this information off the

Internet, many companies will email this information to you.

It's important to understand that just because you have physical access to software that is distributed

on removable media, such as CDs, Zip disks, and diskettes, does not mean that you have the rights to

use that software.

Unless you have a specific license that lets you distribute the software via removable media, you should

not share software CDs or disks with other unlicensed individuals.

Not all software requires that you buy a licence to use it. Shareware is software that is made available

on a trial basis. Those who download it are instructed to pay the shareware creator a small fee if they

like the program and use it frequently.

Freeware is software that is available for free. It's always a good idea to scan downloaded programs

with an antivirus program before using them.

* Privacy of Information Laws

Web sites can collect information about people who access them by adding small data files

called cookies among the files on your PC. Cookies tell sites who you are so you don't have to retype

information about yourself, such as a password, each time that you visit. Cookies can also track Web

sites that you have visited and the purchases made from these sites.

In some countries, Web sites are allowed not only to collect and use this information as intended, but

also to sell the information and distribute it to other organisations and companies. This alarms many

people. They see this activity as an invasion of their personal privacy.

In response to these concerns, many Web sites now contain links to information about the privacy

policies that they follow. Before buying something from a Web site, read its privacy statement.

In 1998, the United Kingdom passed a Data Protection Act that sets rules for processing personal

information and applies to paper records as well as those held on computers.

This Act gives individuals the right to know what organisations are processing their personal data, for

what purpose their data is being processed, and to whom this personal data might be disclosed. It also

gives individuals the right to obtain a copy of this personal data for a nominal fee.

Data protection legislation varies from country to country, but efforts are under way to establish some

international regulations to secure the privacy of information that is distributed across the Internet.

For example, the Safe Harbour agreement ensures that participating U.S. companies meet the stricter

European Union requirements for privacy protection of data transmitted through the Internet.


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In this lesson, you learnt about your obligations when it comes to software licencing agreements and

copyright laws. You now know that when you purchase software, you are responsible for complying with

the company's copyright information.

You also learnt about product IDs and where to locate them so that you will be able to install the

software on your computer.

Finally, you learnt about of the efforts of some governments to protect the privacy of information

transmitted by computers.

Lesson 16. Course in Review

This lesson includes questions, activities, and exercises covering material from the entire course.

You can use it to review and practice applying what you learnt in this course.








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* Exercise 1

Try matching each person in the following list with the kind of application he or she will find most useful

for daily tasks.

Sophia, a journalist who writes and edits her own articles Frank, an accountant who needs to perform difficult calculations to record debits and credits Johnny, a hospital administrator in charge of keeping track of hundreds of patient records Tori, a teacher who wants to show an electronic slide show to her students Wolfgang, an office worker who needs to communicate with his company's overseas office in

writing

Maria, who needs to view some important Internet sites to research her novel Sylvia, who needs to manage her family's finances

Choose from these applications:

Word processor Spreadsheet Accounting Web browser E-mail Presentation Database

Sophia may use a word processor to write and edit her articles. Frank may use spreadsheets for his accounting work. Johnny may use a database to keep track of records. Tori may use a presentation application for her slide show.


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Wolfgang may use e-mail to communicate in writing. Maria may use a Web browser to view Internet sites. Sylvia may use accounting software to manage her family's finances.

concepts of i.t

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