A parity bit is a simple error detection mechanism used in digital communication and data storage. It is an extra bit added to a binary number to ensure that the total number of 1s is either even or odd, depending on the chosen parity scheme. This helps identify errors that may occur during data transmission or storage. There are two types of parity: even parity and odd parity. In even parity, the parity bit is set so that the total number of 1s is even, while in odd parity, it is set to make the total odd. Parity bits are commonly used in systems like computer memory and network communication to enhance data integrity.