What is a "parity" bit?

A "parity" bit is an extra code element added to a set of data bits for the purpose of error detection. When data is transmitted, the parity bit helps verify whether the data has been received accurately. It works by representing the number of bits within the data that are set to one. Depending on whether even or odd parity is used, the parity bit will be set to ensure that the total number of ones in the data plus the parity bit itself is even or odd respectively.

This mechanism is particularly useful in digital communications to detect single-bit errors, allowing the receiving system to identify when data might have been corrupted during transmission. Parity bits are simple to implement and are commonly used in various communication systems to enhance data integrity.

The other options describe different functions that do not pertain to parity bits specifically; therefore, they do not align with the definition or function of a parity bit in data transmission.