Introduction to computer IT-101

Lecture #1

System

Def #1:

• A set of detailed methods, procedures, androutines established or formulated to carryout a specific activity, perform a duty, or solvea problem.

Def #2:

• A group of interacting, interrelated, orinterdependent elements forming a complexwhole.

Sub-system

• A major part of a system which itself has thecharacteristics of a system, usually consistingof several components.

Computer System

• A complete, working system. Computersystems will include the computer along withany software and peripheral devices that arenecessary to make the computer function.Every computer system, for example, requiresan operating system.

Computer System

Why we use Computers ?Why we need IT ?

Introduction to Computer

• An electronic device designed to accept data,perform prescribed mathematical and logicaloperations at high speed, and display theresults of these operations.

Advantages

• It helps you automate various tasks that youcannot do manually.

• It helps you organize your data andinformation in a better way.

• It has much more computing and calculatingpower then an ordinary human.

• It may help your work to be a lot easier.

• It may be the storage of your important dataand files.

Advantages

• It may be your handy book.

• It may help you solve problems faster than anordinary human being can do.

• It has speed, storage, reliability, consistencyand communications.

• It helps you to find useful information usingthe Internet.

• It helps in businesses, factories, offices,schools and homes.

Disadvantage

• It destroys your social life and interactions withhumans if you do not maintain the balance.

• It may effect to the destruction of your eye sightdue to radiation.

• It may cause pimples and wrinkles.

• It may damage your studies and life.

• Too much time in front of monitor may adverseeffect your eye sight and can also make you fat.

Disadvantage

• The way it distracts and can deviate our thoughtsand activities towards unproductive activities.

• It could cause violation of privacy, impact onlabor force, health risks, impact on environment,distraction from work, and possible antisocialinfluences.

• Getting away from their real life and getting intobad lines.

Types of Computer

Computer types can be divided into 3 categoriesaccording to electronic nature.

• Analog Computer

• Digital Computer

• Hybrid Computer

Analogue Computer

• Analogue types of Computer uses what isknown as analogue signals that arerepresented by a continuous set of varyingvoltages and are used in scientific researchcenters.

Digital Computer

• A computer that stores data in terms of digits(numbers) and proceeds in discrete steps fromone state to the next. The states of a digitalcomputer typically involve binary digits whichmay take the form of the presence or absenceof magnetic markers in a storage medium. Indigital computers, even letters, words andwhole texts are represented digitally.

Hybrid Computers• Hybrid computers are the form of computers

which had been designed to display the featuresand characteristics of both computers which arethe analog and the digital computers. When thehybrid computers are used in the form of digitalcomputers then they are deigned to act as thecontroller for the operations carried out in thesystem. When analog is taken into account thenin that case the computer acts as a solutionprovider for different problems that exit and thusby depicting both the feature, it is found to be abeneficial computer.

Classification of Computer

• There are two types of classes

• Classes by size

• Classes by Functions

Classes by size

• Microcomputers (Personal computers)

• Minicomputers (Midrange computers)

• Mainframe computers

• Supercomputer

Classes by functions

• Servers

• Workstations

• Information appliances

• Embedded computers

Microcomputers

• Microcomputers are the most common type ofcomputers used by people today, whether in aworkplace, at school or on the desk at home. E.g.:

• Desktop computers

• Game consoles Laptops

• Notebook computers

• Palmtop computers

• Tablet PC

• Programmable calculator

Minicomputers (Midrange computers)

• A minicomputer is a class of multi-usercomputers that lies in the middle range of thecomputing variety, in between the smallestmulti-user systems (mainframe computers)and the largest single-user systems(microcomputers or personal computers ).

Minicomputers (Midrange computers)

• Computer that possesses the samecomponents as large mainframes but hasreduced memory and slower processingspeeds.

• Contemporary term for this class of system is midrange computer, such as the higher-end SPARC, POWER and Itanium -based systems from Sun Microsystems, IBM and Hewlett-Packard.

Mainframe Computers& Supercomputer

• A very large and expensive computer capable ofsupporting hundreds, or even thousands, of userssimultaneously. In the hierarchy that starts with asimple microprocessor (in watches, for example) at thebottom and moves to supercomputers at the top,mainframes are just below supercomputers.

• In some ways, mainframes are more powerful thansupercomputers because they support moresimultaneous programs. But supercomputers canexecute a single program faster than a mainframe. Thedistinction between small mainframes andminicomputers is vague, depending really on how themanufacturer wants to market its machines.

Servers

• Server is a physical computer (a hardwaresystem) dedicated to running one or moresuch services (as a host) to serve the needs ofusers of the other computers on the network.Depending on the computing service that itoffers it could be a database server, file server,mail server, print server, web servers, or other.

Workstations

• In networking, workstation refers to anycomputer connected to a local-area network.It could be a workstation or a personalcomputer.

Information Appliance

• In information appliance or informationdevice is any machine or device that is usablefor the purposes of computing,telecommunicating, reproducing, andpresenting encoded information in myriadforms and applications.

Information Appliance

• “Information Appliance" (IA) is more specifican appliance that is specially designed toperform a specific user-friendly function suchas playing music, photography, or editing text.

• Smart Phones

• Personal Digital Assistants (PDAs)

Embedded Computers

• Embedded computers can be compared to"computers on a chip". All in one so to speak.You will find them in all kind of appliances thatsurround us. Washing machines, ticketmachines at the subway, camera's, cars,motors, sewing machines, clocks. Everywhereneeding something to regulate, control ofcheck something.