This slide is meant for Class IX CBSE.

1. What is computer?
Computer is an electronic machine
that helps us to store and process
our data and / or instruction at high
speed with accuracy. It can receive
information, perform basic
operations like calculations and
comparisons and produce results
according to the given instructions in
a desirable form.

2. Data and Information:-
• The word data is the plural form of datum, which
means fast . Data are raw facts or the new
,material of information. Data are represented by
symbols. After processing the data, information is
produced.
information is data arranged in an order that would
be useful to the user. Information is produced
due to the output of data processing operations
that is acquired by people to achieve specific
purpose.

3. Data processing consists of three basic activities:
a. Capturing the input data.
b. Manipulating the data and
c. Handling the output results.
DATA
INFORM
ATION

4. Components of computer:
• CPU :The main component of a computer system is
microprocessor. The microprocessor –also known as CPU or
central processing unit.
• Control Unit: Control unit controls all the hardware
operations, i.e.those of input output units, storage and have
the processor itself.
• Arithmetic logic unit(ALU): The arithmetic and logic units in
computers are capable of performing addition, subtraction,
division and multiplication as well as some logical operations.

5. Memory
• The memory or the storage section of the computer
consists of the devices used to store the information
that will be used during the computations. The
memory section of the computer is also used to hold
both intermediate and final results as the computer
proceeds through the program.
Memory can be divided into 2 category :
• 1. Primary
• 2. Secondary

7. • RAM or Random Access Memory: It holds the data and programs that are being
used by the computer at a given time. This is volatile memory, which means the
contents are lost when the computer is turned off.
• ROM OR READ ONLY MEMORY: the ROM is not volatile. That is , contents of ROM
will not get destroyed automatically. A Read Only Memory (ROM), as the name
implies, is a memory unit that performs the read operation only: it does not have the
write capability
PRIMARY MEMORY

8. • SECONDARY MEMORY: The secondary memory
is the memory, which is found outside computer
system. A large quantity of data can be stored
permanently on it. There are various secondary
storage devices and some are:

9. • Characteristic of memory:
1) Speed
2) Storage capacity
3) Access mode
4) Access time
5) Permanence of storage
6) Physical outlooks

10. The data is measured using
some unit.
• In computer terminology ,
• they are called Nibble,
• Bit
• Byte
• Kilo Byte
• Mega byte
• Giga byte
• Tera byte
• Peta Byte
• Exabyte
• Zettabyte

11. Thank You..
• I have created these slides text and pictures
from different sby using the with the help
from google..