Units of information

In a computer, all data is stored in binary form. A binary digit has two possible states, 1 and 0.

A binary digit is known as a bit. A bit is the smallest unit of data a computer can use. The binary unit system is used to describe bigger numbers too.

Eight bits are known as a byte.

The binary unit system is as follows:

8 bits1 byte (B)
1,000 bytes (1,000 B)1 kilobyte (KB)
1,000 kilobytes (1,000 KB)1 megabyte (MB)
1,000 megabytes (1,000 MB)1 gigabyte (GB)
1,000 gigabytes (1,000 GB)1 terabyte (TB)
1,000 terabytes (1,000 TB)1 petabyte (PB)

When calculating storage space for disk drives, it is common to use multiples of 1,000. These are shown in the table above as kilobytes, megabytes etc.

Four bits or half a byte is known as a nibble.