Introduction to
Computer Applications
Lecture 1
What is a Computer?
A computer is an electronic device, which
executes software programs. It consists of
two parts: hardware and software.
2
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.
Hardware
•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.
Software
•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 .
1-3
•E.g. translators, editors, programs.
Types of Computers
•
•
•
•
Supercomputers
Mainframe computers
Minicomputers
Microcomputers
1-4
Page 10
Four Types of Microcomputers
• Desktop
• Notebook or laptop
• Tablet PC
• Handheld
1-5
Page 11
Microcomputer Hardware
• Four basic categories of equipment:
–
–
–
–
System Unit
Input/output
Secondary Storage
Communication
1-6
Page 11
Main Components of a Computer
System Unit
1-7
System Unit
• Two important
components– Processor
– Memory (RAM)
Return
Page 12
1-8
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)
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
10
Input/Output
• Common input devices are the keyboard and the
mouse
• Common output devices are printers and
monitors
Return
Page 13
1-11
Secondary Storage
• 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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1-12
Communications
• 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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Page 14
Software
• Two major kinds of software
– System Software
– Application Software
1-14
Page 7
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
5-15
Page 134
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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Page 135
Application Software
• “End-user” software
• Two major categories
– Basic Application or General purpose
– Specialized applications
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Page 9
Common Features
•
•
•
•
•
•
Graphical User Interface (GUI)
Icons
Windows
Menus
Help
Toolbars
3-18
Page 64
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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Page 68
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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Page 68
Computer Applications:
Spreadsheets
• Programs that manipulate numeric data
• Spreadsheet programs
– Microsoft Excel
– Corel Quattro Pro
– Lotus 1-2-3
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Page 71
Spreadsheet Features
•
•
•
•
•
Workbook files
Worksheet or spreadsheet or sheet
Formulas
Functions
Analytical graphs
or charts
• What-if Analysis
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Page 71
Computer Applications:
Presentation Graphics
• Programs that create visually interesting
presentations
• Presentation programs
– Microsoft PowerPoint
– Corel Presentations
– Lotus Freelance Graphics
3-23
Page 79
Presentation Graphics Features
•
•
•
•
Slides
AutoContent wizard
Design templates
Master slide
3-24
Page 79
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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Page 76
Database Features… study in detail later
• Relational
• Tables
– Records
– Fields
•
•
•
•
Record sorting
Queries
Forms
Reports
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Page 76
Computer Applications
• 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.
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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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Computer Applications
• 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.
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Computer Applications
• Computers in Business
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–
–
–
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.
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Computer Applications…few others
• 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.
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