bit

Information unit

Name	Symbol	Quantity	Expressed in terms of SI base units
bit	bit	data
Definition The bit, symbol bit, is the unit of digital information.   One bit represents a single binary digit which can be either 0 or 1.

The bit is the smallest unit of information and storage.

Number bases

In the decimal number system, numbers are represented as groups of digits. Each digit can represent any value from 0 to 9. Numbers greater than 9 are represented by additional digits to the left, forming an array of digits. Each additional digit increases the number of different values that can be represented by a factor of 10.

In binary, numbers are also represented as groups of digits. However, the value that each digit can represent is restricted to either 0 or 1. Numbers greater than 1 are represented by additional digits to the left, forming an array of digits in a similar manner to the decimal system. In binary, each additional digit increases the number of different values that can be represented by a factor of 2.

The nibble

A nibble is a group of 4 bits. The nibble is used in the context of hexadecimal numbers, since a nibble has the same amount of information as one hexadecimal digit. A group of 4 bits can be used to represent 2⁴, or 16, different values.

binary (base 2)	hexadecimal (base 16)	decimal (base 10)
0000	0	0
0001	1	1
0010	2	2
0011	3	3
0100	4	4
0101	5	5
0110	6	6
0111	7	7
1000	8	8
1001	9	9
1010	A	10
1011	B	11
1100	C	12
1101	D	13
1110	E	14
1111	F	15

The byte

The byte, symbol B, is a unit of digital information consisting of a group of 8 bits. A group of 8 bits can represent 2⁸, or 256, different values.