2. Computer
A computer is an electronic device used to
process data, converting data into information
that is useful to people.
A computer is a machine that is used to store
and process data electronically.
A computer is an electronic device which is
used to store, retrieve and process data
according to a set of instructions (program)
given to it.
Input Output
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4. Understand the Basic Concepts of Hardware,
Software and Information Technology (IT).
5. Hardware
◦ The term hardware refers to the physical
components of the computer such as the
system unit, mouse, keyboard, monitor etc.
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Lesson 4
6. Software
◦ The software is the instructions that makes
the computer work.
◦ Software is held either on your computers
hard disk, CD-ROM, DVD or on a floppy disk
and is loaded from the disk into the
computers RAM (Random Access Memory),
as and when required.
8. All computers have the following basic
components :-
1. Input devices:-
For reading data into main memory
2. Central processing unit(CPU):-
For processing the data held in main memory
3. Main memory :-
Holds current executing programs
4. Auxiliary storage:-
For long term storage
5. Out put devices:-
For displaying , printing and outputting information
9. The processor:-
The processor has the following functions:-
1. It controls the transmission of data from input devices to
main memory
2. It processes the data held in main memory
3. It controls the transmission of information from main memory
to out put devices
10. The main memory:-
A memory is a location that is divided into millions of
addressable storage units called bytes.
1Kelobyte (KB)=1024 bytes
1Megabyte(MB)=1024*1024 bytes
1Gigabyte(GB)=1024*1024*1024bytes
1Terabyte=(TB)=1024*1024*1024*1024bytes
11. There are two types of main memory:-
1. RAM:-
-Random Access Memory
-Read and write memory
-Volatile memory
- Holds current executing programs
