Computer – Memory Units

Memory unit is the amount of data that can be stored in the storage unit. This storage capacity is expressed in terms of Bytes.

The following table explains the main memory storage units −

S.No. Unit & Description
1 Bit (Binary Digit)

A binary digit is logical 0 and 1 representing a passive or an active state of a component in an electric circuit.

2 Nibble

A group of 4 bits is called nibble.

3 Byte

A group of 8 bits is called byte. A byte is the smallest unit, which can represent a data item or a character.

4 Word

A 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. 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 computer words.

The following table lists some higher storage units −

S.No. Unit & Description
1 Kilobyte (KB)

1 KB = 1024 Bytes

2 Megabyte (MB)

1 MB = 1024 KB

3 GigaByte (GB)

1 GB = 1024 MB

4 TeraByte (TB)

1 TB = 1024 GB

5 PetaByte (PB)

1 PB = 1024 TB