A parity bit is a technique in computer systems used to detect and correct errors that occur during transmission. There are many other terms that are often used interchangeably with the term "parity bit". These synonyms include error-correcting code, check bit, checksum, and redundancy bit. All of these terms refer to the same concept of adding an extra bit to a sequence of bits to ensure that the number of 1s in the sequence is even or odd. These techniques are crucial in ensuring the integrity of data and preventing errors from occurring during transmission, which can lead to corrupted or unusable data.