This document provides an overview of the computer system. It discusses what a computer is, data processing, applications of computers, and the importance and limitations of computers. It then describes the parts of a computer system, including hardware, software, users, data/information, procedures, and communication. The hardware components of a computer are also outlined.

1. Md. SOHAG SIKDER
Northern University
Bangladesh

2. CIT 1101
Introduction to Computers

3. An Overview of the
Computer System
Lecture 1

4. In this lecture you will learn about:
Computer
Data Processing
Applications of Computers
Importance of Computers
Limitations of Computers
Parts of Computer System
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5.  Computers are everywhere
5
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6.  A Computer is an electronic data processing
machine that stores, retrieves and
processes data. Finally generate
meaningful information with speed and
accuracy.
 Computer is an electronic device that
process data according to a set of stored
instructions.
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7. Fig. Data Processing Cycle
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Processes
(Data Processing)
Input
(Data)
Output
(Information)
Storage
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8. Numbers
Images
Sound
Video
Input Process Output
12 + 8 = 20
000001100
000001000
---------------
000010100 20
0010000000000000000
0100000000000001001
0110000011000011011
0111111111111001111
1111111111111011111
1111111111100011111
000001000 000001001 000010100 …
volume  Time 
00101010111
11010101010
01010101010
11110100011
00101011011
8 9 0 5 …
00101010111
11010101010
01010101010
11110100011
00101011011
00101010111
11010101010
01010101010
11110100011
00101011011
00101010111
11010101010
01010101010
11110100011
00101011011
00101010111
11010101010
01010101010
11110100011
00101011011
Text This is a test 84 104 73 115 … This is a test

9.  Data is the raw materials from which
information is generated.
 Data consists of raw facts, numbers,
letters, or symbols that the computer
processed into meaningful information.
 Data has no specific meaning.
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10.  It’s a process that converts the data into
information.
 A general term that stands for all logical,
arithmetic, and input/output operations
that can be performed on data by a
computer.
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11.  Information refers to an organized ,
meaningful, & useful interpretation of data
 Information is the result of processing,
manipulating and organizing data in a way
that adds to the knowledge of the receiver.
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12. Monthly Sales Report
for West Region
Sales Rep: Charles Mann
Emp No. 79154
Item Qty Sold Price
TM Shoes 1200 $100
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13.  Data and information are stored/ maintained for
future use.
 Any type of information - words, figures, still or
moving images, sound or music - can be stored
into storage devices (e.g. HDD, CD, DVD) and
that can be used at any time.
Hard Disk Drive
CD / DVD DriveFlash Drive
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14. CPU
Memory
Input Output
Storage
Figure: Block diagram of a Computer System.
Process
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15.  Data processing and Data storing
 In Banking system : On line banking
 Internet & Webpage :Information super highway
 E mail
 E commerce and M commerce
 Airways and Railways Ticket Reservations
 Medical science
 In Education
 Multimedia system
 Production system
 Communication: Mobile communication
 Publishing (Books, Newspaper)
 Offices
 Data Analysis, Data Base Management
 Job searching / CV sending
 And More…
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16.  High Speed: Computer can perform data
processing jobs very fast, usually measured in
microseconds (10-6), nanoseconds (10-9) and
picoseconds (10-12)
 Automatic Operation: Computers are
automatic in operation. Once data and
program are fed to a computer, operation of
the computer is automatic.
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17.  Accuracy: Accuracy of a computer is
consistently high and degree of its
accuracy depends upon its design.
Computer errors causes due to incorrect input
data or unreliable programs.
The system or process of showing the faulty
results of a computer is called Garbage-In-
Garbage-Out (GIGO)
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18.  Diligence: Computer is free from monotony,
tiredness, and lack of concentration. It can
continuously work for hours without creating
any error and without grumbling
 Versatility: Computer is capable of
performing almost any task, if the task can be
reduced to a finite series of logical steps
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19.  Power of Remembering: Computer can
store and recall any amount of
information because of its secondary
storage capability. It forgets or looses
certain information only when it is asked
to do so
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20.  Common data: One item of data can be
used for different computer operation.
 Complexity: Computers perform complex
calculations. A computer provides the
required answers after running the
program for complex calculations.
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21.  Computer cannot think (no I.Q).
 Computer can not do anything without
human instructions.
 Computers can not make any
adjustment as human being can do (no
feelings).
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22. Creativity,
Judgment,
Intuition
Speed,
Accuracy,
Attention
to Details,
No I.Q,
No feelings
Power of Remembering, Processing Capability,
Versatility / Adaptability
Computer Human
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23.  Systems: A system is a collection of
elements or components that are organized
for a common purpose.
 A computer system consists of hardware
components that have been carefully
chosen so that they work well together and
software components or programs that run
in the computer.
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24. Hardware
Software
Users
Data / Information
Procedures
Communication (optional)
A computer system is made up of six parts:
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25. The physical devices that make up the
computer are called Hardware.
The generic term device refers to any
piece of hardware.
Examples: CPU, memory, disks, CD-ROM
drives, printer, monitor etc.
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27. Graphics
Onboard and
external
Power
supply
Processor
—under
the fan and
heat sink
Keyboard, video,
and other connectors
Disk drives
RAM
Expansion slots
Motherboard
IDE
SATA

28. Step by step instructions that tells the
hardware how to perform a task.
The term program refers to any piece of
software.
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System Software
• Operating system – Win XP, Win 7, Win 10, LINUX
• Utility program – Antivirus, Partition magic, Screen Saver
Application Software
• Web browser, Word processors, Adobe Photoshop, Games etc.
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29. People are the Computer operators, also
known as users or Humanware.
The user is a person perhaps like yourself –
someone without much technical knowledge
of computers but who uses computers to
perform professional or personal tasks,
enhance learning, or have fun.
No computer is totally autonomous.
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30. Data is the raw materials from which
information is generated.
information is summarized data or
otherwise manipulated (processed) data.
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31. Procedures are descriptions of how
things are done, steps for accomplishing
a result.
Procedures for computer systems appear
in documentation manuals, which
contain instructions, rules and guidelines
to follow when using hardware and
software.
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32. When one computer system is set up to
share data and information electronically
with another computer system,
communications becomes a sixth system
element.
Examples: phone lines, microwave
transmission, satellite transmission, etc.
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