An extra bit used in checking for errors in groups of data bits transferred within or between computer systems. With PCs, the term is frequently encountered in modem-to-modem communications, in which a parity bit is often used to check the accuracy with which each character is transmitted, and in RAM, where a parity bit is often used to check the accuracy with which each byte is stored.
(Computer science) An error detection procedure in which a bit (0 or 1) added to each group of bits so that it will have either an odd number of 1's or an even number of 1's.