Area where we store Data or Information is called as computer data
storage, in other way we can call it as storage
or memory, this is a main functionality
of computer. All type of manipulations and computations performed in the central
processing unit (CPU) of a computer. As per the Von Neumann architecture, the
CPU is made up of two main parts: control unit(CU) and arithmetic logic unit
(ALU). The control unit controls the flow of data between the CPU and memory,
while ALU performing any arithmetic or logical operations on data. The most
common unit of storage is the byte, and 1 byte is equal to 8 bits. 1 bit is
nothing but alphabet, numbers, pictures pixel, audio, video, or any other form
of data or information can be converted into a string of bit, or binary number
form, which is a value of 1 or 0. Below table will specify the units of memory
storage.
|
Sr. No.
|
Unit
|
Description
|
|
1
|
1 Bit
|
A binary digits as 0 & 1
|
|
2
|
1 Nibble
|
A group of 4 bits
|
|
3
|
1 Byte
|
A group of 8 bits, and 2 nibbles
|
|
4
|
1 Word
|
It is group of byte, which varies from computer to computer, but is
fixed for each computer
|
|
5
|
1 Kilobyte (KB)
|
1024 bytes
|
|
6
|
1 Megabyte (MB)
|
1024 KB
|
|
7
|
1 Gigabyte (GB)
|
1024 MB
|
|
8
|
1 Terabyte (TB)
|
1024 GB
|
|
9
|
1 Petabyte (PB)
|
1024 TB
|
Memory storage types:
Memory storage is again divided in three sections, which are
primary storage, secondary storage and Tertiary storage.
I]Primary storage:
CPU has direct access to Primary storage or it is referred simply as main memory
or internal memory. As CPU is directly connected with main memory by memory bus
so CPU continuously read the instruction from the memory and stored data to the
main memory. This is volatile storage means it lose the data when there is
power supply interrupt at any time. i.e. RAM(Random Access Memory)
II]Secondary storage:
Secondary storage is known as external memory or auxiliary storage, which is differs
in functionality from primary storage as it is not directly accessible by the
CPU. There is not direct connection from CPU. The computer usually uses its input/output
channels to access secondary storage. Secondary storage does not lose the data
when there is power supply interrupt at any time, so it is known as non-volatile
storage. i.e. ROM(Read Only Memory), CD or DVD
