computer fundamentals

1 Mr. Adeniyi A. Adejo

NICE Gambia Training Institute

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Basic PC Fundamentals

Importance of using computers

Computers play a key role in how individuals work and how they live. Even the smallest organizations have computers to help them operate more efficiently, and many individuals use computers at home for educational, entertainment, and business purposes. In this session, you will learn the basics about computers, the history of computers, the different categories of computers, hardware and software, and maintaining your computer. You will also learn about computer applications in education and explore various technology issues that are related to computers such as security, privacy and ethics.

Brief History of computers

Nearly 5,000 years ago the abacus emerged in Asia Minor. The abacus may be considered the first computer ever man made by man. This device allowed its users to make computations using a system of sliding beads arranged on a rack. Early shopkeepers used the abacus to keep up with transactions. The use of pencil and paper spread, the abacus lost its importance. Nearly twelve centuries past before the next important advance in computing devices emerged.

In 1642, Blaise Pascal, the 18-year-old son of a French tax collector, invented what he called a numerical wheel calculator to help his father with his duties. The Pascaline, a brass rectangular box, used eight movable dials to add sums up to eight figures long. Pascal's device used a base of ten to achieve this. The disadvantage to the Pascaline, of course, was its limitation to addition. In 1694, Gottfried Wilhem von Leibniza a German mathematician and philosopher improved the Pascaline by creating a machine that could also multiply. Like its predecessor, Leibniz's mechanical multiplier worked by a system of gears and dials.

The real beginning of computers began with an English mathematics professor, Charles Babbage. Babbage's steam-powered Engine outlined the basic elements of a modern general purpose computer and was a breakthrough concept. The Analytical Engine consisted of over 50,000 components. The basic design included input devices in the form of perforated cards containing operating instructions and a "store" for memory of 1,000 numbers of up to 50 decimal digits long.

It was not until 1981, when IBM introduced its personal computer (PC) for use in the home, office and schools. The 1980's saw an expansion in computer use in all three arenas as clones of the IBM PC made the personal computer even more affordable. The number of personal computers in use more than doubled from 2 million in 1981 to 5.5 million in 1982. Ten years later, 65 million PCs were being used. As computers became more widespread in the workplace, new ways to harness their potential developed. As smaller computers became more powerful, they could be linked together, or networked, to share memory space, software, information and communicate with each other. Computers continue to grow smaller and more powerful.



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Lesson 1

Introduction to Basic Computer Fundamentals

Information Technology (IT) is a term used to describe all the types of technology that are used to create, store, exchange or use information in its various forms, for example: computer data, voice conversations, still images, motion pictures, etc. The Internet, the World Wide Web, mobile telephony, cable and satellite television are all prime examples of the so called “information revolution” generated by IT technology. It is the technology that has driven the massive expansion of the mobile phone, media, computer and computer network industries for the last decade or more. In a nutshell, IT is a convenient term that encompasses telephony, media, computer and all other associated technologies in the same word. Information Systems (IS) are the subset of IT technologies that are primarily concerned with the storage, manipulation and movement of information within or between computer systems. In other words it is all about computers and computer networks.

Computer Basics You don't have to know everything to be comfortable with computers. But there is a

lot of information that will help you understand why things are the way they are... and how you can find help when required!

"Knowledge is power!" So it's to your advantage to gather all the knowledge that you can. Besides which, computers are lots of fun - when they aren't driving you crazy!!!



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What's in these lessons?

The lessons in these Computer Basics fundamentals of NICE Education explain briefly, what you hear about computers. The goal is to learn enough that you can follow along as computer technology becomes more and more important in our world.

Consider this set of lessons "Beginning Driver's Education" for the computer. What might be covered in a Driver's Education course in a Driving school? How the engine works. Parts of the car. How to turn it on? How to shift gears? Rules of the road. Laws. Proper signaling. Lane changing. Basic maintenance. Changing a flat. Filling up with gas. Some clues on when "You'd better stop the car now!"

The topics covered here will introduce you to a similar set of topics about computers. When you finish, you'll be just as prepared to "drive" a computer, as you were to drive a car when you finished Driver's Education. Scary thought, isn't it? That clearly means you will need lots of practice with a skilled "driver" in the passenger's seat before you can be considered "safe on the road!" But we can get you started! But, really, you'll understand the basic ideas behind computers, some of the ills that affect computers, and some of the basic safety measures to take to keep your computer healthy. You'll gain some knowledge of how we got to today's computers and what lies ahead. It'll be great!

Computers and Computing. Overview. As previously mentioned, „Information Systems‟ technologies are concerned with the handling and movement of information within and between computers. They are technologies that are designed around computers, computing and computer networks. Computers come in three sizes; large, medium and small. At the „big‟ end there are the Supercomputers and mainframes used by large organizations and research facilities. At the other end is the humble PC or desktop/laptop computer, millions of them worldwide. Whatever the size the basic definition is the same. In general; A computer is: An electronic device, which is used for processing, organising and storing information.



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Structure of the Computer System

The Components of a PC system.

A complete computer system is divided into two major parts or categories. Hardware Software

Such a a computer system is either a: 1. stand alone 2. Network computer

A complete system has four functional parts, such as Input, Processing, Output and Storage.

What is a computer and The Information Processing Cycle?

A computer is an electronic device that executes the instructions in a program. The information processing circle are the ways data is received by the computer process it produce the result and the storage of information for later used.

PROCESSING INPUT DATA OUTPUT

Secondary Storage



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Structure of the Computer System

The Personal Computer (PC). A Personal Computer (PC) is a general-purpose electronic device which is used for processing, organising and storing of information. It takes information in, processes it in some way, and then outputs (and usually stores) the result. The information that is processed is in the form of words, numbers and pictures.

Keyboard

Mouse

Scanner

Modem

Digital Camera

Microphone

Joystick

Monitor/Screen

Printer

Projector

Speaker

Computer System

Hardware Software

System Unit Peripherals

RAM None Volatile

ALU Control Unit Input Devices Output Devices



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Computer Basics Computers are showing up everywhere you look, and even in places you can't see. Computers check out your groceries, pump your gas, dispense money at the ATM, turn the heat on and off, control the way your car runs. They're everywhere! They're everywhere!

In fact, the computer is rapidly becoming, if it hasn't already gotten there, as tightly woven into the fabric of our lives as the automobile. The analogy runs quite deep.

When automobiles were new, many people said "Those smelly, loud, complicated things will never replace the horse!" And "Those things break down in just a few miles, while my faithful horse goes on and on and repairs itself!" Nowadays it's hard to imagine the world without all the variety of four-wheeled, internal combustion vehicles. How many can you name? Sedans, pickup trucks, fire engines, front-end loaders, 4-wheelers, golf carts, bulldozers, cranes, vans, dump trucks... We have an "automobile" for every purpose under heaven - and in different models and colors, too.

Do you know all these vehicles?

So it is with computers. There are different kinds of computers for different purposes. They are just as varied in size, expense, and ability as our more familiar 4-wheeled

vehicles are.

There is a computer for every use in an work environment. Let's look at the kinds of computers that there are, based on general performance levels.

Some Beginning Terms

Hardware: the physical parts of the computer that you can touch or feel.

Software: the programs (instructions) that tell the computer what to do.

Data: are raw facts that need to process like first name, price, and quantity ordered

Information: is data that has been process into a useful form, like a complete mailing address

Default: the original settings; what will happen if you don't change anything.

What makes a computer powerful?



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Speed: A computer can do billions of actions per second. Reliability: Failures are usually due to human error, one way or another. Storage: A computer can keep huge amounts of data.

Example of computers in different size

Computers for personal use come in all shapes and sizes, from tiny PDAs (personal digital assistant) to hefty PC (personal computer) towers. More specialized models are announced each week - trip planners, expense account pads, language translators....

Hand-held (HPC)

PDA

Tablet PC

Laptop/Notebook

Desktop

Tower

Workstation



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System Components

Overview of Systems and Components

One of the great strengths of the PC platform, which has led to its great success in the market, is its modularity. Most PCs are made up of many different individual components, which can be mixed and matched in thousands of different configurations. This lets you customize the PC you either buy or build to meet your exact needs.

Even though, not all systems have the same structure many modern operating systems share the same goal of supporting the following types of system components.

The System Unit. The system unit (the system box that the monitor sits on) contains all the internal components of a PC system. It houses the Central Processing Unit (CPU) and various supporting Integrated Circuits (called chips) all of which are fixed to Printed Circuit Board (PCB) called the motherboard. The system unit also houses disk drives, expansion slots and the PC power supply unit.



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PC Peripherals Monitor.

The monitor (the computer screen) is the primary device for displaying information from the computer.

Keyboard.

The keyboard is the primary device for entering information into the computer. There are three types of keys on a computer keyboard: Alphanumeric keys; Letters and numbers. Punctuation keys; full stop, comma, semicolon, etc. Special keys; Function keys, control keys, arrow keys, etc.

Mouse. The mouse is the primary device for navigating the computer screen and interacting with the computer.

Modem.

A modem (MOdulator-DEModulator) is a device that allows computer information to be transmitted across the telephone network. The sending PC‟s modem translates (modulates) digital computer data into analog signals that can then be carried over a telephone line. The receiving modem converts (demodulates) the analog data back into digital form. A connection of the kind is known as a „dial up‟ connection, the modem literally „dials‟ the receiving modem and a connection is then established. Most PC‟s have a modem already installed in the system unit, if not, an external modem can be connected to one of the PC‟s serial ports.

A) Input device Information and programs are entered into the computer through Input devices such as the keyboard, mouse, etc or through other computers via network connections or modems connected to the Internet. The input device also retrieves information off disks.

What is Input?

Everything we tell the computer is Input.

Types of Input

Data is the raw facts given to the computer.

Programs are the sets of instructions that direct the computer.

Commands are special codes or key words that the user inputs to perform a

task, like RUN "ACCOUNTS". These can be selected from a menu of commands like "Open" on the File menu. They may also be chosen by clicking on a command button.



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User response is the user's answer to the computer's question, such as

choosing OK, YES, or NO or by typing in text, for example the name of a file.

Keyboard Layout and Data Entry

ENTER or RETURN - Moves the cursor down one line and to the left margin. Enter also process commands such as choosing an option in a dialog (message) boxes and submitting a form.

DEL or DELETE - Deletes the character at cursor and/or characters to the right of

the cursor and all highlighted (or selected) text.

BKSP or BACKSPACE - Deletes the character to the left of cursor and all

hightlighted text.

SPACE BAR - Moves the cursor one space at a time to the right

SHIFT KEY - Use the shift keys to type capital letters and to type the upper character on keys with two characters on them

CAPS LOCK - Locks the keyboard so it types capital letters (a light goes on when caps lock is on)

TAB - Moves the cursor five spaces to the right (number of spaces are usually adjustable). Tab moves to the next field in a form or table (Shift-Tab for previous field).

ESC or ESCAPE - Cancels a menu or dialog box

ARROW KEYS - Moves the cursor around document without changing text

FUNCTION KEYS or F KEYS - Access commands by themselves or in combination

with the three command keys; CTRL, SHIFT, and ALT

Command or Special Keys

Command keys normally do nothing on their own but work in combination with other keys. Each piece of software uses the command keys differently though there is a move to standardize some functions. The Control key or Ctrl is often used to access commands. The Alternative key or Alt is often used to access menus. The Shift key is used to type CAPITAL LETTERS. As well the command keys are all

used to move through documents and edit text faster and easier. As well many computers have Special keys design specifically for the particular computer. Apple computers have the Apple keys and Macs have Command keys. Many keyboards now have a Windows key specifically for Windows 9x and newer systems. Many

older computers also have special keys used for a variety of different functions.

Some Notebook or Laptop keys are left out because of space limitations and they usually have a Special function key which allows other keys to double for the missing ones.



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Basic Typing Rules

Place one space between each word, after a punctuation mark and at the end of a sentence. Always start a sentence with a capital letter. Use capitals for names, addresses, provinces and countries, places, organizations, businesses, associations, schools, colleges, universities, days of the week, months, holidays, nationalities, ethnic groups and languages.

Learning the keyboard is the first step to learning computers. Learning involves practice. It really is as simple as that. There are two kinds of typing.

The first is called Touch Typing. The Touch Typist uses the Home Keys (asdf for

the left hand and jkl; for the right) and all the fingers on both hands as well as the thumbs for the Space Bar while typing. There are many commercial and public domain programs that are designed to teach this method.

The other method is some times called 'Hunt and Peck' or depending on finger strength 'Search and Destroy'. This involves using one or more fingers on one or two hands to type. It is a perfectly acceptable way of using a computer and many people get along fine with this technique.

Microphone

Used to put sound into a computer Need sound recording software

Scanner

A scanner allows you to scan documents, pictures, or graphics and view them on the computer. You can also use software to edit the items you scan.

Used to put printed pictures and text into a computer Converts an image into dots that the computer can

understand To scan text, optical character recognition (OCR) software

is needed



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Digital Camera

Used to take electronic pictures of an object The pictures taken by a digital camera can be used directly

by a computer

B) Processing System Units (Process data)

Processing is the thinking that the computer does - the calculations, comparisons,

and decisions. People also process data. What you see and hear and touch and feel is input. Then you connect this new input with what you already know, look for how it all fits together, and come up with a reaction, your output. "That stove is hot. I'll move my hand now!"

The kind of "thinking" that computers do is very different from what people do.

Machines have to think the hard way. They do one thing at a time, one step at a time. Complex procedures must be broken down into VERY simple steps. Then these steps can be repeated hundreds or thousands or millions of times. All possible choices can be tried and a list kept of what worked and what didn't.

People, on the other hand, are better at recognizing patterns than they are at single facts and step-by-step procedures. For example, faces are very complex structures. But you can identify hundreds and even thousands of different faces.

A human can easily tell one face from another, even when the faces belong to strangers. You don't recognize your mothers´ face because you remember that Mom's face is wide or 2.5 cm wide, and has a scar on the left side! You recognize the whole pattern of Mom's face. There are probably a lot of folks with noses the size and shape of Mom's. But no one has her whole face.

But a computer must have a lot of specific facts about a face to recognize it. Teaching computers to pick Mom's face out of a crowd is one of the hardest things scientists have tried to do yet with computers. But babies do it naturally!

So computers can't think in the same way that people do. But what they do, they do excellently well and very, very fast.

C) Output devices produces output: is data that has been processed into

useful form, now called Information. E.g. Monitor/Screen, Printer, Project etc

Types of Output

Hard copy:

Information printed on paper or other permanent media



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Soft copy: This is a file saved on the computer and displays on screen or by other non-permanent means need by the user.

D) Storage devices stores results Storage refers to the media and methods used to keep information available for later use. Some things will be needed right away while other won't be needed for extended periods of time. So different methods are appropriate for different uses. Earlier when learning about processing, we saw all the kinds of things that are stored in Main Memory. E.g. Hard disk, Flash disk, etc.

Main Memory = Primary Storage

Main memory keeps track of what is currently being processed. It's volatile,

meaning that turning the power off erases all of the data.

For Main Memory, computers use RAM, or Random Access Memory. These

memory chips are the fastest, but most expensive, type of storage.

Auxiliary Storage = Secondary Storage Auxiliary storage holds what is not currently being processed. This is the stuff that is "filed away", but is ready to be pulled out when needed.

It is nonvolatile, meaning that turning the power off does not erase it.

Auxiliary Storage is used for:

Input - data and programs Output - saving the results of processing

So, Auxiliary Storage is where you put last year's tax info, addresses for old customers, programs you may or may not ever use, data you entered yesterday - everything that is not being used right now.



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Process Management

The operating system manages many kinds of activities ranging from user programs to system programs like printer spooler, name servers, file server etc. Each of these activities is encapsulated in a process.

It is important to note that a process is not a program. A process is only ONE instant of a program in execution. There are many processes can be running the same program. The five major activities of an operating system in regard to process management are

Creation and deletion of user and system processes. Suspension and resumption of processes. A mechanism for process synchronization. A mechanism for process communication. A mechanism for deadlock handling.

File Management

A file is a collected of related information defined by its creator. Computer can store files on the disk (secondary storage), which provide long term storage. Some examples of storage media are magnetic tape, magnetic disk and optical disk. Each of these media has its own properties like speed, capacity, data transfer rate and access methods.

A file system normally organized into directories to ease their use. These directories may contain files and other directions.

The five main major activities of an operating system in regard to file management are

1. The creation and deletion of files. 2. The creation and deletion of directions. 3. The support of primitives for manipulating files and directions. 4. The mapping of files onto secondary storage. 5. The back up of files on stable storage media.



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Lesson 2: Starting the Computer

Introduction to Linux Operation System

This chapter does not go into great detail or cover advanced topics in Linux. Instead, we want you to hit the ground running.

Linux History

Linux was written by Linus Torvalds and has been improved by countless number of people around the word. It was initially developed for small PC.

We assume very little here about your background, except perhaps that you have some familiarity with personal computer systems, and MS-DOS. However, even if you're not an MS-DOS user, you should be able to understand everything here. At first glance, Linux looks a lot like MS-DOS--after all, parts of MS-DOS were modeled on the CP/M operating system, which in turn was modeled on UNIX. However, only the most superficial features of Linux resemble MS-DOS. Even if you're completely new to the PC world, this tutorial should help.

And, before we begin: Don't be afraid to experiment. The system won't bite you. You can't destroy anything by working on the system. Linux has built-in security features to prevent ``normal'' users from damaging files that are essential to the system. Even so, the worst thing that can happen is that you may delete some or all of your files and you'll have to re-install the system. So, at this point, you have nothing to lose.

Basic Linux concepts.

Linux is a multitasking, multi-user operating system, which means that many people can run many different applications on one computer at the same time. This differs from MS-DOS, where only one person can use the system at any one time. Under Linux, to identify yourself to the system, you must log in, which entails entering your login name (the name the system uses to identify you), and entering your password, which is your personal key for logging in to your account. Because only you know your password, no one else can log in to the system under your user name.

On traditional UNIX systems, the system administrator assigns you a user name and an initial password when you are given an account on the system. However, because in Linux tt you are the system administrator, you must set up your own account before you can log in. For the following discussions, we'll use the imaginary user name, ``lamin.''

In addition, each system has a host name assigned to it. It is this host name that

gives your machine a name, gives it character and charm. The host name is used to



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identify individual machines on a network, but even if your machine isn't networked, it should have a host name.

Desktop applications

When most people hear the word "software" they think of the e-mail and word processing

applications on their own individual computer. These applications fall into the category of

"desktop applications". Common desktop applications include e-mail clients, web browsers,

accounting software, spreadsheets, and presentation tools.



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What is open source?

The term "open source" refers to software that can be freely redistributed, analysed and

modified by anyone. Key characteristics of open source software include:

Free: The software doesn't cost anything to obtain – although there are costs involved

in configuring and maintaining it, just like with other software;

Open: Because the software code is open and readable by anyone, it also means that

the software can be modified by anyone with programming skills ... allowing for the

translation of software into local languages or the addition of features needed by a

particular group;

Collaborative: Open source software draws its strength from the fact that people who

improve, modify or customise programs must give it back to the open source

community so others can benefit from their work.

How does a piece of software become open source? The people who created it decided to

release it under a license such as the General Public License (GPL) that meets the criteria of

the "open source definition" outlined above. It is often said that open source licensing is

"viral" because people who modify a piece of software must release their modifications

under the same open, free and collaborative conditions of the original software. i

Open source: the electronic equivalent of generic drugs

Like the generic drugs that have transformed health care provision in the South, open source

software is royalty and license free, and is therefore substantially cheaper to acquire than

branded alternatives. The reason for this is that open source software is developed by

volunteer collectives who are not seeking to profit from its sale.

In addition, just as the recipe for generic drugs is made public, so the source code or inner

workings of open source software is accessible to the user. Any qualified person can see

exactly how the software works and can easily make changes to the functionality.

Who's using open source?

More and more organizations in business and government are turning to open source. Large

computer companies like IBM, Sun and Apple have embraced open source as a part of their

software strategy. Governments have turned to open source both as a way to share software

they create and as a way to lower costs, with the City of Munich switching all 14,000 of its

computers to Linux, an open source operating system. And, of course, the large majority of

computers used to run the Internet run open source tools, with 65% of web servers currently

running the Apache web server.

The same trend is beginning to happen within civil society, especially in relation to server

software and web applications. Civil society examples include:



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An estimated 90% of Greenpeace servers worldwide run Linux. Also, Greenpeace's

global virtual private network is built on top of open source tools. iii

More and more companies uses open source operating systems, e-mail clients and

office applications tools to provide Internet access and training to their customers.

Human rights organizations around the world have begun to adopt the Martus

software, an open source package that allows users to document incidents of abuse by

creating bulletins, uploading them at the earliest opportunity, and storing them on

servers located around the world.

The Association for Progressive Communications uses open source for a wide

variety of applications including its global network of web mirrors that are used to

fight corporate and government censorship around the world.

Heritage seed bank Seeds of Diversity uses open source database tools to store and

management of horticultural data.

OneWorld.net has adopted open source content management and online community

systems to run its global network of portals.

These examples are only the tip of the iceberg. This is because the open source revolution is

in some ways a quiet one. Most organizations just download open source and use it, not

taking the time or effort to tell anyone about it. Yet, certainly, the numbers are growing.

Why use open source?

There has been a great deal of discussion of the benefits of open source for civil society of

late. There have been workshops, papers, speeches and even manifestos expounding on the

virtues of the open source / civil society connection. Amidst all of this, it may seem that open

source is being presented as some sort of cure all. Certainly, it is not. Yet, used with an

understanding of its limitations and challenges, open source software does present some clear

benefits to civil society organizations:

Lower information technology costs: Open source eliminates the need to pay for

software licenses. Of course, this does not mean that you can eliminate information

technology costs altogether – there is still a need for staff and equipment to make it

all work. But open source can definitely lower overall costs, especially for

organizations which need advanced servers, databases and web applications.

Flexible software solutions: The fact that the code is "open" means that software can

be modified to respond to needs not addressed by the original developer. The most

obvious benefit of this responsiveness is the ability to translate software into local

languages. However, it is also useful for web applications where it may be desirable

to add on new features that accommodate the unique needs of civil society

organizations.

Better security: Mature open source applications – Linux, Apache, Send Mail,

OpenOffice.org – tend to be more secure than their proprietary counterparts. This is

partly due to the fact that the code is open, allowing system administrators and others

concerned with security to quickly identify problems and propose solutions to the



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lead software developers. Also, open source applications tend not to be targeted by

people who make viruses. This kind of improved security is vital for civil society

organizations who want keep unwanted "snoopers" out of their network and who

cannot afford the downtime that comes with virus attacks.

Collaborative, cooperative values: Open source is based on a set of collaborative

and cooperative values. It assumes that we can create more useful tools by working

together than we can by competing. Using open source is not only a way to support

these values, but it can also provide a way to learn from them. The open source

community presents a very practical and adaptable example of how organizations can

work collaboratively.

It is interesting to note that civil society organizations are starting to turn to open source

methods for more than just software. The "free, open, collaborative" model provides a useful

approach for developing written content, multimedia, analytical and evaluation frameworks

and many other "knowledge products". For example, this guide has been released under a

Creative Commons open content license that encourages others to modify it as long as they

release their modifications for free.

Creating an account.

Before you can use NICE systems, you must have a user account for yourself. It's usually not a good idea to use the same account for all users.

Note: you don‟t have to forget your passwords otherwise you cannot log in.

Logging in to the Emaganda

After starting your computer, you will be asked to enter your user name and password for the system to verify before you log in. At login time, you'll see a prompt resembling the following: Username: Password

Enter your user name and press the Arrow key down.

Next, enter your password. The characters you enter won't be seen at the screen, so type carefully. If you mistype your password, you won‟t see the message. Once you have correctly entered the user name and password, you are officially logged in to the NICE Emaganda system, and you are free to roam.

Lesson 3: Using Linux Operating System Customizing the Desktop Interface



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Introduction to Desktop

When you start a desktop session for the first time,

you should see a default startup screen, with panels, windows,

and various icons.

The major components of the GNOME Desktop are as follows:

Desktop

The desktop itself is behind all of the other components on the desktop. You can place

objects on the desktop to access your files and directories quickly, or to start applications that

you use often.

Panels The panels are the two bars that run along the top and bottom of the screen. By default, the

top panel shows you the GNOME main menu bar, the date and time, and the launcher for the

GNOME help system and the bottom panel shows you the list of open windows and the

workspace switcher.

Panels can be customized to contain a variety of tools, such as other menus and launchers,

and small utility applications, called panel applets. For example, you can configure your

panel to display the current weather for your location.

Windows Most applications run inside of one or more windows.

You can display multiple windows on your desktop at the same time.

Windows can be resized and moved around to accommodate your workflow.

Each window has a titlebar at the top with

buttons which allow you to minimize, maximize, and close the window.

Workspaces

You can subdivide your desktop into separate workspaces. Each workspace can contain

several windows, allowing you to group related tasks together.

Windows

Types of Windows

There are two main types of window:

Application windows



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Application windows allow minimize, maximize and close operations through the buttons on

the title bar. When opening an application you will usually see a window of this type appear.

Dialog windows

Dialog windows appear at the request of an application window. A dialog window may alert

you to a problem, ask for confirmation of an action, or request input from you.

For example, if you tell an application to save a document, a dialog will ask you where you

want to save the new file. If you tell an application to quit while it is still busy, it may ask

you to confirm that you want it to abandon work in progress.

Some dialogs do not allow you to interact with the main application window until you have

closed them: these are called modal dialogs. Others can be left open while you work with the

main application window: these are called transient dialogs.

Creating a Folder

To create a folder, perform the following steps:

1. Select the folder where you want to create the new folder.

2. Choose File → Create Folder. Alternatively, right-click on the background of the

window, then choose Create Folder. An untitled folder is added to the location. The

name of the folder is selected.

3. Type a name for the folder, then press Return.

Duplicating a File or Folder

To create a copy of a file or folder in the current folder, perform the following steps:

Select the file or folder that you want to duplicate.

Choose Edit → Duplicate. Alternatively, right-click on the file or folder, then choose

Duplicate.

A copy of the file or folder appears in the current folder.

Closing Folders

To close folders you may simply click on the close window button, this however may not be

the most efficient way to close many windows. If you would like to view only the current

folder, and not the folders you opened to reach the current folder, choose File → Close

Parent Folders.

If want to close all folders on the screen, choose File → Close All Folders.



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Renaming a File or Folder

To rename a file or folder perform the following steps:

Select the file or folder that you want to rename.

Choose Edit → Rename. Alternatively, right-click on the file or folder, then choose

Rename. The name of the file or folder is selected.

Type a new name for the file or folder, then press Return.

Deleting a File or Folder

When you delete a file or folder, the file or folder is not moved to Trash, but is deleted from

your file system immediately. The Delete menu item is only available if you select the

Include a Delete command that bypasses Trash option in the File Management Preferences

dialog.

To delete a file or folder perform the following steps:

Select the file or folder that you want to delete.

Choose Edit → Delete. Alternatively, right-click on the file or folder, then choose

Delete.

Applications Menu

The Applications menu contains a hierarchy of submenus, from which you can start the

applications that are installed on your system.

Each submenu corresponds to a category. For example, in the Sound & Video submenu, you

will find applications for playing CDs and recording sound.

To launch an application, perform the following steps:

1. Open the Applications menu by clicking on it.

2. Move the mouse down the menu to the category the application you want is in. Each

submenu opens as your mouse passes over the category.

3. Click the menu item for the application.

When you install a new application, it is automatically added to the Applications menu in a

suitable category. For example, if you install an instant messenger application, a VoIP

application, or an FTP client, you will find it in the Internet submenu.

Lesson 4: Working with files

The Desktop The desktop lies behind all other components on your screen. When no windows are visible,

the desktop is that part of the screen between the top and bottom panels. You can place files

and folders on the desktop that you want to have easy access to.



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The desktop also has several special objects on it:

The Computer icon gives you access to CDs, removable media such as floppy disks,

and also the entire filesystem (also known as the root filesystem). By default, you do

not have the security permissions to read other users' files or edit system files.

Your Home Folder, labelled username's Home, where all of your personal files are

kept. You can also open this folder from the Places menu.

The Trash is a special folder in which to place files and folders you no longer need.

When you insert a CD, a flashdrive, or other removable media, or a device containing

files such as a music player or a digital camera, an icon representing this device will

appear on the desktop.

As you work with your computer, the desktop becomes obscured by the windows you

are working with. To quickly reveal the desktop by minimizing all windows, you can

do one of the following:

Either action will also restore your windows to their previous state. Alternatively, you can

switch to another workspace to see the desktop.

You can change the color of the desktop background or the image displayed there.

Desktop Background Preferences

The desktop background is the image or color that is applied to your desktop. You can open

Desktop Background Preferences by right-clicking on the desktop and choosing Change

Desktop Background, as well as from the System → Preferences menu.

You can customize the desktop background in the following ways: Select an image for the

desktop background. The image is superimposed on the desktop background color. The

desktop background color is visible if you select a transparent image, or if the image does not

cover the entire desktop.

Select a color for the desktop background. You can select a solid color, or create a gradient

effect with two colors. A gradient effect is a visual effect where one color blends gradually

into another color.

You can also drag a color or a pattern to the desktop from the Backgrounds and Emblems

dialog in the Nautilus file manager.

Workspaces

Workspaces allow you to manage which windows are on your screen. You can imagine

workspaces as being virtual screens, which you can switch between at any time. Every

workspace contains the same desktop, the same panels, and the same menus. However, you



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can run different applications, and open different windows in each workspace. The

applications in each workspace will remain there when you switch to other workspaces.

Using Trash in Linux

Trash is a special folder that holds files that you no longer want to keep. Files in the Trash

are not deleted permanently until you empty the trash. This two-stage process is in case you

change your mind, or accidentally remove the wrong file.

You can move the following items to Trash:

Files

Folders

Desktop objects

If you need to retrieve a file from Trash, you can display Trash and move the file out of

Trash. When you empty Trash, you delete the contents of Trash permanently.

To Display Trash

You can display the contents of Trash in the following ways:

From a file browser window

Choose Go → Trash. The contents of Trash are displayed in the window.

From a spatial window

Choose Places → Trash. The contents of Trash are displayed in the window.

From the desktop

Double-click on the Trash object on the desktop.

To Empty Trash

You can empty the contents of Trash in the following ways:

From a file browser window

Choose File → Empty Trash.

From the desktop

Right-click on the Trash object, then choose Empty Trash.

Note: When you empty trash, you destroy all files in the trash. Be sure that the trash only

contains files you no longer need.

Lesson 5: Understanding the Internet

What Is the Internet?

In this section...

How Does the Internet Work?

The History of the Internet

What Kinds of Information are Available?

Mozila Firefox

Nescape Navigator

Internet Explorer

Opera

Example of Internet Browsers



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How Do People Use the Internet?

It seems like everyone's talking about the Internet these days. But what is it really? How does

it work? How do you access it? And most important, what can it do for you at work or at

home?

Fortunately, accessing and using the Internet is fairly simple. Let this tutorial be your guide

to the Internet as you connect for the first time and explore the network's vast and useful

resources.

How Does the Internet Work?

The Internet is a worldwide collection of computer networks, cooperating with each other to

exchange data using a common software standard. Through telephone wires and satellite

links, Internet users can share information in a variety of forms. The size, scope and design

of the Internet allow users to:

connect easily through ordinary personal computers and local phone numbers;

exchange electronic mail (E-mail) with friends and colleagues with accounts on the

Internet;

post information for others to access, and update it frequently;

access multimedia information that includes sound, photographic images and even

video; and

Access diverse perspectives from around the world.

An additional attribute of the Internet is that it lacks a central authority—in other words,

there is no "Internet, Inc." that controls the Internet. Beyond the various governing boards

that work to establish policies and standards, the Internet is bound by few rules and answers

to no single organization.

In February 1996, President Clinton signed into law the Communications Decency Act,

which provides criminal penalties for those who post or transmit "indecent" material via the

Internet. This law, however, has been challenged in U.S. courts by those who feel it would

unfairly prohibit many legitimate uses of the Internet, and was ruled unconstitutional in July

1996. The federal government, however, is preparing an appeal.

The History of the Internet

Many people think that the Internet is a recent innovation, when in fact the essence of it has

been around for over a quarter century. The Internet began as ARPAnet, a U.S. Department

of Defense project to create a nationwide computer network that would continue to function

even if a large portion of it were destroyed in a nuclear war or natural disaster.

During the next two decades, the network that evolved was used primarily by academic

institutions, scientists and the government for research and communications. The appeal of

the Internet to these bodies was obvious, as it allowed disparate institutions to connect to

each others' computing systems and databases, as well as share data via E-mail.



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The nature of the Internet changed abruptly in 1992, when the U.S. government began

pulling out of network management, and commercial entities offered Internet access to the

general public for the first time. This change in focus marked the beginning of the Internet's

astonishing expansion.

According to a survey conducted by CommerceNet and Nielsen Media Research in early

1997, nearly one out of every four Americans over the age of 16 is an Internet user. And the

number of users worldwide is believed to be well into the tens of millions. Other statistics are

equally startling:

A CNN report stated that Internet traffic in 1996 was 25 times what it was just two

years earlier.

The market research group IntelliQuest pegged the number of Internet users in the

U.S. in late 1996 at 47 million - a 34 percent increase over the first quarter of that

year.

According to IBM, 146 countries currently have at least some level of Internet access.

The technology research firm IDG estimates that by century's end, one billion people

worldwide will have access to personal computers—more than doubling the

computer-savvy population of 1996.

The Internet explosion coincides with the advent of increasingly powerful yet reasonably

priced personal computers with easy-to-use graphical operating systems. The result has been

an attraction of recent computer "converts" to the network, and new possibilities for

exploiting a wealth of multimedia capabilities.

What Kinds of Information are Available? In addition to text documents, the Internet makes available graphics files (digitized

photographs and artwork), and even files that contain digitized sound and video. Through the

Internet, you can download software, participate in interactive forums where users post and

respond to public messages, and even join "chats," in which you and other users type (and, in

some cases, speak) messages that are received by the chat participants instantly.

How Do People Use the Internet? Obviously, the Internet can bring you a whole host of capabilities. But how can they be put to

practical use?

Among the ways that users like you are taking advantage of the Internet are:

Sharing research and business data among colleagues and like-minded individuals.

Communicating with others and transmitting files via E-mail.

Requesting and providing assistance with problems and questions.

Marketing and publicizing products and services.

Gathering valuable feedback and suggestions from customers and business partners.

The Internet's potential is limited only by users' vision and creativity. And as the Internet

grows, new and innovative uses will surely follow.



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What Is the World Wide Web?

Of all the worthwhile features of the Internet, none has captured the public's imagination and

contributed to the Net's growth so much as the World Wide Web. A method of posting and

accessing interactive multimedia information, the "Web" is a true "information

superhighway," allowing users the world over to access a wealth of information quickly and

easily.

1968

ARPA awarded the ARPANET contract to BBN. BBN had selected a Honeywell

minicomputer as the base on which they would build the switch. The physical network was

constructed in 1969, linking four nodes: University of California at Los Angeles, SRI (in

Stanford), University of California at Santa Barbara, and University of Utah. The network

was wired together via 50 Kbps.

1973

Development began on the protocol later to be called TCP/IP; it was developed by a group

headed by Vinton Cerf from Stanford and Bob Kahn from DARPA. This new protocol was to

allow diverse computer networks to interconnect and communicate with each other.

1974

The first use of term Internet was by Vint Cerf and Bob Kahn in paper on Transmission

Control Protocol

The History of the Web

The first rumblings toward this concept began immediately after World War II, when

scientists were desperately seeking ways to organize and share their accumulated wartime

research. In 1945, noted scientist Vannevar Bush published an essay in Atlantic Monthly

titled "As We May Think," which proposed a massive information index that people from all

over the world could access and search. Although Bush's system was mechanical (and was

never developed), his essay had a profound impact on many who would one day help design

the Internet and the World Wide Web. For this reason, Vannevar Bush is often hailed as the

theoretical father of the Web.

Given this background, the actual Web was originally conceived as a way for physicists to

share their research data. In 1989, Tim Berners-Lee led a team at Switzerland's European

Particle Physics Laboratory (CERN) in developing the initial World Wide Web standards.

Key among these was the use of hypertext, or "hot" portions of an online document that,

when selected, take the user to a related, or "linked," document. For instance, if a user was

reading a Web document about dinosaurs and selected the hypertext word "Tyrannosaurus,"

he or she would go directly to a document dealing specifically with that species of dinosaur.

http://www.isg.sfu.ca/%7Educhier/misc/vbush/



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Computerized hypertext was pioneered by researcher Ted Nelson in a system called Xanadu,

which he created in the early 1960s. Although Xanadu was never fully realized, many of the

Web's developers—including Berners-Lee—have cited it as an influence on their work.

The next great innovation for the Web came in 1992, when programmers from the National

Center for Supercomputing Applications (NCSA) at the University of Illinois developed the

Mosaic browser, a software application that displayed not only the text of a Web document

(or page), but embedded graphic elements as well. By bringing multimedia to the Web,

Mosaic vested it with enormous potential.

Today, several Web browsers are available for IBM, Macintosh and UNIX-based computers,

and most of the major online services include Web browsers in their standard software

packages. And the Web is growing at a phenomenal rate. According to Interactive Week

magazine, the number of Web servers (computers that store Web pages) surged from fewer

than 3,500 in April 1994 to more than 40,000 in July 1995. And in February 1997, the

computing firm Network Wizards determined the number of commercial domains alone to be

well over 700,000.

What Else Makes the Web Unique?

We have already cited hypertext and multimedia as two of the outstanding features of the

World Wide Web. Among the Web's other distinct advantages are:

Open standards that allow Web pages to be viewed through most any computer with

an Internet connection and a Web browser.

The ability to make software and data files available for downloading.

Ease of use; just point and click on your browser to access the information you need.

For the individual or organization wishing to distribute information, the Web makes

"publishing" easy and cost-effective. Putting information on the Web is quite inexpensive

compared with traditional publishing, yet puts that information before a potential audience of

millions. And unlike a printed publication, a Web document can be revised and updated at

any time.

What Does the Web Empower Me to Do?

The World Wide Web brings you all of the advantages of the Internet—and more! Among

the things that the Web allows you to do are:

Publish and make frequent updates to on-line documents, and receive direct feedback

on those documents via E-mail.

Connect with a diverse, global audience—a community defined not by geography,

but by interests.

Keep abreast of the latest news and developments in your profession... often before

such news appears in conventional media.

Reference other Web resources easily via hypertext.



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Access otherwise obscure information not readily available in other media.

Download useful software at little or no cost.



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A Quick Tour of a Typical Web Site

A Web site may consist of a single Web page, or may comprise multiple, interconnected

pages. The following is a view of how the NICE Gambia home page appears through a

popular browser:

1. Browser tools help you navigate around the Web. These vary among browsers, but most

include tools for moving back and forth between pages, saving data to your hard disk,

and controlling how Web pages will appear on your screen.

2. A "Bookmark" list, "favorites" list or "hotlist" lets you save the names and locations

of favorite sites for easy reference (usually accessible through pull-down menus).

3. The Uniform Resource Locator (URL) is the address of a Web site. URLs for Web

pages begin with the code http:// ("http" stands for hypertext transfer protocol).

4. Some Web pages contain special graphic buttons that, when clicked, take you to another

resource as would a regular hotlink.

5. Hypertext hotlinks are connections to other pages and resources. To access, just click on

them with your mouse or trackball. Most pages contain hotlinks throughout the text, as

well as lists of links to other sites judged by the author/sponsor to be of particular

interest. Some sites contain hotlinks to places where you can download software, listen to

a sound file, or view a video clip.



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CenterSpan is among more elaborate Web sites that contain forms, where you can submit

information in an easy-to-follow format, and bulletin board features that allow you to post

information for others to see.

What is Email - Electronic Mail The first e-mail program was created by Ray Tomlinson of BBN in 1972. The Advanced

Research Projects Agency (ARPA) was renamed The Defense Advanced Research Projects

Agency (or DARPA). The ARPANET was currently using the Network Control Protocol or

NCP to transfer data. This allowed communications between hosts running on the same

network.

Email is shorthand term meaning Electronic Mail. Email much the same as a letter, only that

it is exchanged in a different way. Computers use the TCP/IP protocol suite to send email

messages in the form of packets. The first thing you need to send and received emails is an

email address. When you create an account with a Internet Service Provider you are usually

given an email address to send from and received emails. If this isn't the case you can create

an email address / account at web sites such as yahoo, hotmail and Lycos.

Structure of an E-Mail Message

The header of an email includes the From:, To:, Cc: and Subject: fields. So you enter the

name and address of the recipient in the Fom: field, the name and address of anyone who is



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being copied to in the Cc: field, and the subject of the message obviously in the Subject:

field.

The part below the header of the email is called the body, and contains the message itself.

Spelling the correct address is critical with an email. Like with a normal postal letter, if you

get the address wrong it won't go the correct receiver. If you send an email to an address

which doesn’t exist the message will come back to you as a Address Unknown error routine.

Email Addresses

An e-mail address typically has two main parts: That is the (@) and dot () all emails must

contain this elements otherwise you can’t use it.

[email protected]

The first field is the user name (editor) which refers to the recipient's mailbox. Then there is

the sign (@) which is the same in every email address. Then comes the host name (internet-

guide), which can also be called the domain name. This refers to the mail server address,

most usually having a individual IP address. The final part of an email address includes the

top-level domain (TLD). For the above address this is 'co.uk', which is for commercial sites

based in the UK.

Email Attachment Defined, what is an email attachment?

Email Attachment

This is the name given to a file that is sent with an email, an email attachment can be any

type of file including images (photos), documents, zipped files/folders, etc.

Most email providers have a limit on the size of the attachment that can be sent, also, you can

only send up to a certain amount of attachments with each email.

Bear these file size limits in mind when sending attachments, the size of the attachment you

are sending may be acceptable by your email provider but may be too big for the recipient's

email account.

Attaching a file to an email

To send a file (photo, document, etc) with an email you have to attach it in a special way to

the email.

The process for attaching a file to your emails will vary depending on which email provider

you use or which program you use to compose your emails, but generally, look for a button

or link when you are composing the email that says attachments, attach file or edit

attachments.

Usually you will be presented with a browse button, click on this button, navigate to the



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folder with the file in that you want to send, and then select the file.

To finish attaching the file will depend on the email provider's interface, if you are using an

email client such as Outlook then the file will be attached automatically.

Downloading the attachment from a received email

To download or view the attachment will again depend on your email provider or the

program you use to retrieve your email.

WARNING: downloading attachments can be dangerous, always scan any attachments for

viruses before opening them with up-to-date anti-virus software.

If using a mail client such as Outlook then there is normally an option under the FILE menu,

such as save attachments (in outlook), select this and then choose where you want to save

the file.

If you get your email via webmail then the process is usually straight forward, look for a

button or link such as save attachment, download attachment, get attachment, or

something similar.

Your browser (if using webmail) may ask you whether you want to open or save the file, to

download the file choose save/download and then navigate to the folder where you want to

store the attachment.

What Are The Good Search Engines? There are over 300 Internet search engines available for free use. All of them have their

individual merits, and they each use different techniques for how to catalog the billions of

web pages around the world.

I) Five major "search engines" do stand out, however, for their massive catalogs of

information: Google.com and its Amazon.com variant, Msn.com, Yahoo.com, A9.com,

AllTheWeb.com, AskJeeves.com, Vivisimo.com and Dogpile.com.

These five database engines use "spiders" (automated programs) to read thousands of pages

per day, and index them for easy finding later.

II) Three major "search directories" also stand out for their voluminous catalogs:

Yahoo's Directory, DMOZ.org, and About.com. Different from search engines, these three

search directories use human editors and reader submissions to hand-pick their cataloged

content. With human reading being much slower than robot spiders, you can expect search

directories to be much smaller than search engines. The human editor element, however, does

add the filter of human judgment, which can help cut down the drivel you have to sift

through when searching.

III) So, when it comes to the question, "which search tool is the best?", the real question

should perhaps be: "which search tool do you personally prefer?" Google.com has the least



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advertising on its screen, and the most indexed content of all the search engines. DMOZ is

slower to load, but it has excellent depth of content. Vivisimo uses "clustering" to present

results in categorized format. About.com has lots of advertising, but has amazing subject

matter expertise. Ask Jeeves, Dogpile, and AllTheWeb have their pros and cons, too. There

are almost 300 other search tool choices not even listed here. Whichever you personally

prefer, every one of these search tools contains more content than you or I could ever read in

a lifetime! The smart choice, accordingly, would be to test and compare these major search

tools by yourself.

Don't settle for one search tool! Use different search engines and directories in

combination! Not only do search tools change their appearance every few months, you are

also more likely to locate higher-quality web pages when you combine the high volume of

spider content, and the hand-picked reviewing of human editors. Rotate your search tools,

avoid the rut of relying on only one search engine, show some perseverance and patience,

and you will get good results.

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