bit stands for

Concept: A great deal of computing vocabulary is built by blending — a descriptive multi-word phrase contracted into one short word, as in picture element → pixel, modulator–demodulator → modem, and coder–decoder → codec. Separately, the binary (base-2) number system uses exactly two symbols, 0 and 1, and a single position of a base-2 numeral is called a binary digit. Reading such a short word therefore means recovering the phrase it was contracted from.

Application: The word "bit" is the blend of the phrase "binary digit": the letters "bi" of binary joined to the letter "t" of digit give "bit". It therefore names one position of a base-2 numeral, holding either 0 or 1. The coinage is credited to John W. Tukey and was first published by Claude Shannon in A Mathematical Theory of Communication (1948); ITU-T Recommendation B.14 and the NIST glossary both record "bit" as the abbreviation of "binary digit".

Cross-check — what the other phrases name:

• binary tree — a data structure in which each node links to at most two children; the basis of binary search trees, heaps and expression trees.

• Bivariate Theory — statistical vocabulary: bivariate analysis studies two variables together, as in bivariate correlation or regression.

• binary information term — three general words placed side by side: base-2 encoding, the quantity measured in information theory, and a named expression; contracting them does not produce the three-letter word.

Hence bit stands for binary digit. Eight bits make one byte, and n bits can represent 2n distinct values.