Computer - Memory Units


  • It is the amount of data that can be stored in the storage unit.

  • The storage capacity are expressed in terms of Bytes.

Following are the main memory storage units:

Sr. No.UnitDescription
1Bit (Binary Digit)A binary digit is logical 0 & 1 representing a passive or an active state of a component in an electric circuit.
2NibbleA group of 4 bits is called nibble.
3ByteA group of 8 bits is called byte. A byte is the smallest unit, which can represent a data item or a character.
4WordA computer word like a byte, is a group of fixed number of bits processed as a unit which varies from computer to computer but is fixed for each computer.
The length of a computer word is called word-size or word length and it may be as small as 8 bits or may be as long as 96 bits.
A computer stores the information in the form of the computer words.


Few higher storage units are the following:

Sr. No.UnitDescription
1Kilobyte (KB) 1 KB = 1024 Bytes
1Megabyte (MB) 1 MB = 1024 KB
1GigaByte (GB) 1 GB = 1024 MB
1TeraByte (TB) 1 TB = 1024 GB
1PetaByte (PB) 1 PB = 1024 TB