digit

A digit is an element of a set that, taken as a whole, comprises a system of numeration. Thus, a digit is a number in a specific context. In the decimal (base-10) Arabic numbering system, the digits are the elements of the set {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}.

In the binary number system, the digits are the elements of the set {0, 1}. This system is used by computers because the two digits can represent the logic low and high states. The term "binary digit" is compressed to " bit " in computer parlance. Other numbering systems used in computing include the octal and hexadecimal systems. In the octal number system, the digits are the elements of the set {0, 1, 2, 3, 4, 5, 6, 7}. In the hexadecimal system, the digits are the elements of the set {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F}.

The term "digit" is often used to represent a number in a specific position in a larger number, or in a number with a fraction expressed using a radix point. For example, in the decimal number 2609.37, the number 2 is the thousands digit, the number 6 is the hundreds digit, the number 0 is the tens digit, the number 9 is the ones digit, the number 3 is the tenths digit, and the number 7 is the hundredths digit.

In biology and anatomy, the term refers to a finger or toe of a human or animal. In robotics, the term can refer to any small, useful appendage in an end effector (robot hand).