Computer Memory Types
There are two types of computer memory
1. Internal Memory
2. External Memory
1. Internal Memory (Primary Memory)
This memory is known as the primary memory of the computer. This memory is mounted on the motherboard of the computer.
There are 3 sub-types of this Internal Memory
i) RAM
ii) ROM
iii) Cache
i) RAM ( Random Access Memory ) :-
The information stored in the computer's memory can be used as long as the current is flowing. This information is erased when the power is cut off. This is why this memory is called temporary memory.
ii) ROM ( Read only Memory ) :-
We can only read the information in this memory but not change the original information. Hence it is called Read only Memory (ROM). Even if the computer is turned off, the information in this memory is not erased.
iii) Cache Memory :-
Cache memory is known as a temporary memory. The cache memory estimates what data the processor needs at a given time and the data is loaded into the cache memory.
2. External Memory (Secondary Memory) :-
External Memory contains some memory devices as follows.
A) Magnetic Disk and Hard Disk :-
These devices are used to store a large amount of information. It contains multiple discs instead of one. Information is stored on both surfaces of each disk. The speed of reading and writing information on this disk is high.
B) Pen Drive (Flash Drive) :-
This type of drive can be connected to a computer using a USB port. It has a capacity of 4 GB to 1 TB. Nowadays most use of the pen drive to transfer data from computer.
C) Flash Memory Cards :-
Flash memory cards are used to store information in various devices such as Mobile Phones, Digital Cameras, MP3 Players. The capacity of this memory ranges from 2 GB to 256 GB. The above information can be easily transferred to the computer and the unwanted information can be deleted
D) Optical Disks :-
There are 2 types of optical discs.
a) CD (Compact Disk) :-
In this CD you can store different types of data. That data cannot be deleted once stored. It has a capacity of 650 MB to 1 GB. But there are different types.
1.
CD-ROM This type of CD already contains information. It already contains information like songs, movies, computer games, software.
2.
CD-R CDs are available in the market as Black CDs. In this you can store the information you want to store. But once stored, the information cannot be deleted.
3.
CD-RW This type of CD allows you to store or delete information any number of times.
b) DVD (Digital Varsatile Disk) :-
This DVD can store more information than CD. The capacity of this DVD is from 4.7 GB to 17 GB. But there are some types like CD. There are 3 types of DVD-ROM, DVD-R, DVD-RW. The higher the capacity of this DVD, the more you use it.
