Introduction to Computer Applications

Lecture 1

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What is a Computer?

A computer is an electronic device, which executes software programs. It consists of two parts: hardware and software.

Computer Systems• A computer program is…

– A set of instructions for a computer to follow.• Computer software is …

– The collection of programs used by a computer• Computer hardware is …

– The actual physical machines that make up a computer installation.

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Software Hardware

•The parts that can’t be touched are called “Software”. Characteristics: It has no physical existence. •They can be realized through mind and feeling only .•E.g. translators, editors, programs.

•Things that can be touched are called “Hardware”.•Characteristics: They have physical existence, weight, color & they can be damaged or broken.•E.g. monitor, mouse, printer.

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Types of Computers

• Supercomputers• Mainframe computers• Minicomputers• Microcomputers

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Four Types of Microcomputers

• Desktop

• Notebook or laptop

• Tablet PC

• Handheld

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Microcomputer Hardware• Four basic categories of equipment:

– System Unit– Input/output– Secondary Storage– Communication

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Main Components of a Computer

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System Unit

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System Unit

• Two important components-– Processor– Memory (RAM)

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Slide 1- 9

Processor (CPU)• The CPU (Central Processing Unit) is the brain of

the computer.

• The CPU follows the instructions in a program and

performs the calculations specified by the program.

• CPU has two important units

– ALU ( Arithmetic logic unit does arithmetic &

logical operations for computer)

– Control unit ( controls the flow of information in

computer)

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Hardware• Memory

– Internal memory / Main memory• Random Access Memory (RAM)

– Main feature 1: volatile requires continuous supply of electrical power to retain information

– Functions: Receive commands / data from keyboard Store information ready to be sent to output Store currently running programs/their data Store immediate data generated by the currently

running programs

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Input/Output

• Common input devices are the keyboard and the mouse

• Common output devices are printers and monitors

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Secondary Storage

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• Unlike memory, secondary storage holds data and programs even if electrical power is not available

• The most important types of secondary media are floppy, hard, and optical disks e.g, CDROMs

Memory Storage Devices

Less capacity Larger capacity

Volatile -> Data is lost when power is off Non-volatile-> Data is retained even if power is off

More expensive Less expensive

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Communications

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• Communication devices enable microcomputers to

communicate with other computer systems across

the globe.

• The modem is the most widely used communication

device.

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Software

• Two major kinds of software

– System Software

– Application Software

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System Software

• Handles technical details• Works with end users, application software, and

computer hardware• Four types of programs

– Operating system– Utilities– Device drivers– Language translators

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Operating System

• Coordinates computer resources• Provide an interface between the users and

computer• Runs applications• A collection of programs that handle technical

tasks• Every computer has an operating

system

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• “End-user” software• Two major categories

– Basic Application or General purpose– Specialized applications

Application Software

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Common Features

• Graphical User Interface (GUI)• Icons• Windows• Menus• Help• Toolbars

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Computer Applications:Word Processors

• Used to create text-based documents– Memos, letters, and faxes– Newsletters, manuals, and brochures

• Word processing programs – Microsoft Word– Corel WordPerfect– Lotus Word Pro

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Word Processor Features• Word Wrap• Editing

– Thesaurus– Find and Replace– Spelling and grammar checkers– Copy and paste features– Add images to your document

• Formatting– Font and font sizing– Character effects – Bulleted and numbered lists

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Computer Applications:Spreadsheets

• Programs that manipulate numeric data• Spreadsheet programs

– Microsoft Excel– Corel Quattro Pro– Lotus 1-2-3

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Spreadsheet Features

• Workbook files• Worksheet or spreadsheet or sheet• Formulas• Functions• Analytical graphs

or charts• What-if Analysis

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Computer Applications:Presentation Graphics

• Programs that create visually interesting presentations

• Presentation programs – Microsoft PowerPoint– Corel Presentations– Lotus Freelance Graphics

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Presentation Graphics Features

• Slides• AutoContent wizard• Design templates• Master slide

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Computer Applications: Database Management Systems DBMS

• A collection of related data• Sets up a structure for data storage• Database programs

– Microsoft Access– Corel Paradox– Lotus Approach

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Database Features… study in detail later

• Relational• Tables

– Records– Fields

• Record sorting• Queries• Forms• Reports

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• Internet - It is a network of almost all the computers in the world. You can browse through much more information than you could do in a library. That is because computers can store enormous amounts of information. You also have very fast and convenient access to information.

Computer Applications

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Common Internet Uses

• Communicating – Exchange e-mail– Discussion Groups – Video conferencing

• Online shopping or e-retailing or e-tailing– Cybermall– E-bay

• Searching– Virtual Libraries

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Common Internet Uses

• Entertainment: Music, Games, Movies

• Education or e-learning : Instead of a book it is easier to learn from an E-learning software.

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• Computers in Medicine - – You can diagnose diseases. You can learn the cures. – Software is used in magnetic resonance imaging to examine the

internal organs of the human body. – Software is used for performing surgery. – Computers are used to store patient data.

Computer Applications

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• Computers in Business– Shops and supermarkets use software, which calculate the bills. – Taxes can be calculated and paid online. – Accounting is done using computers. – One can predict future trends of business using artificial

intelligence software. – Software is used in major stock markets. – One can do trading online. – There are fully automated factories running on software.

Computer Applications

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• Banks - All financial transactions are done by computer software. They provide security, speed and convenience.

• Travel - One can book air tickets or railway tickets and make hotel reservations online.

• Telecommunications - Software is widely used here. Also all mobile phones have software embedded in them.

• Airplanes – Pilots train on software, which simulates flying.

• Weather analysis – Supercomputers are used to analyze and predict weather.

Computer Applications…few others