parity check

A parity check is a method used in information theory to detect errors in data. It involves adding an extra bit, called a parity bit, to a block of binary digits. This parity bit is set so that the total number of '1's in the block (including the parity bit) is either always even or always odd, depending on the chosen parity scheme (even or odd parity).12

If an error occurs during data transmission, changing a bit from 0 to 1 or vice versa, the parity of the block will change. The receiving end can then perform the same parity check. If the parity doesn't match the expected scheme, it indicates that an error has occurred. While parity checks can detect single-bit errors, they cannot correct them or detect errors where an even number of bits are flipped. This makes them a simple form of error detection, often used in conjunction with other methods for more robust error control.23