A computer accepts data as input, processes it using programs, and produces output. It has four basic functions: input, processing, output, and storage. Data becomes information after being processed. A computer system has two main components - hardware which are the physical devices, and software which are the programmed instructions. Common hardware includes input devices like keyboards, processing devices like the CPU, output devices like monitors, storage devices like hard drives, and communication devices like modems. System software manages the hardware and allows other programs to run, while application software allows users to perform tasks.

1. What is computer?
Brief Understanding
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2. What is computer?
A computer is a device that accepts information / data by
input, manipulates it for some result based on a program /
sequence of instructions on how the data is to be
processed, generate result as output and store in their
storage as needed.
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3. Primary operation of computer
The four basic operation describe in computer definition;
Input – entering data into the computer
Processing – performing operation on the data
Output – presenting the result
Storage – saving data, programs, and output results
IPOS Cycle
The sequence of input, processing on data, generating
output, and storage is also referring to IPOS Cycle /
information processing cycle.
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4. Data vs. Information
Data - User inputs into a computer is Data, likes raw
material before data processing. Data maybe relates as
facts, events, transactions, images, songs, and
documents. Data is also refers to unprocessed
information.
Information - When data is processed into meaningful
format, by specific program, it becomes information.
Information is also know as results.
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5. Example - Student admission form, at time of submission
college collect required student data like name, age,
pervious history of education, certificates, picture and
signature. When admission department process in their
system with some specific program (student enrolment
software), after successful students get admission and
issuing student ID card, student ID card is information of
student.
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6. Primary components of computer
Today computer system have two major components, as
following;
Hardware - all physical devices like input, processing,
output, storage, and communication are Hardware.
Software - all computer define instructions / programs,
which may operate hardware and process user input data
for output, known as Software.
Example – a cassette player and its cassettes are
hardware, but the songs recorded on the cassettes are its
software. To listen to a song, that song has to be
recorded on one of the cassettes first, which is then
mounted on the cassette player and played.
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7. Relation - all hardware devices like keyboard, CPU, LCD,
HDD, and modem are physically assemble in one unit
(computer system), computer software / system software
(may install on HDD ) execute following devices in
manner full way, and user define program / application
software generate results.
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8. Computer Hardware
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9. There are five major category of hardware devices, as
per their functionally,
1) Input devices - an input device is any piece of
equipment that is used to input data into the computer.
Keyboard – Joystick -
Mouse – Scanner -
Microphone - Touch screen –
Digital pen - Fingerprint -
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10. 2) Processing devices - The main processing device for a
computer is the central processing unit (CPU).
Motherboard – Processor -
RAM – VGA Card -
Power supply - Casing –
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11. 3) Output devices - The output device accepts processed
data from CPU and present the result to the user.
Monitor / LCD – Printer -
Plotter – Speaker -
Headphone - Projector –
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12. 4) Storage devices - Storage devices are used to store
data like input data, processing software, and generate
results output.
HDD – USB -
DVD drive – DVD -
Floppy drive - Floppy –
Zip drive - Zip disk –
Tape drive - Tape cartridge -
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13. 5) Communication devices - Communication devices
allow users to communicate electronically with others,
access remote information via internet from home /
school / company computer network.
Modem – NIC -
DSL / ISDN – Wireless USB -
Wireless modem - Mobile –
Wi-Fi - Bluetooth -
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14. Computer Software
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15. There are two major category of computer software, as
per their functionally,
1) System Software - The programs that allow a
computer to operate and manage hardware are
communally known as system software.
System software also refers as operating system;
Which start up computer (means boot)
Control its primary operation
Manage hardware devices
Boot process
Boot process sequences;
Turn on power button
During boot “kernel” of operating system loaded into memory
Computer does quick diagnostic it self
Load “shell” of operating system – desktop
Lunches any application software like antivirus for cleaning
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16. Examples –
Windows XP –
Red Hat -
MAC OS X –
Google Chrome OS –
Solaris Unix -
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17. 2) Application Software - Application software consists of
programs designed to allow people to perform specific
tasks using a computer.
Application software load at operating system kernel.
There are dozens of applications software types like;
Publishing software, animation software, presentation
software, word processing software, viewing web pages,
record keeping (data base) software, developing
languages, an etc.
Examples –
MS Office – Norton antivirus -
Photoshop - WinZip -
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18. EA games –
Chrome browser -
Oracle 10g database –
Java –
Yahoo messenger -
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