Parity Bit

  Also called Check bit.
  . Added to block of data for error detection purpose.
  . Used in data transmission to ensure total number of 1's is even or odd.
  . Purpose is to ensure data is not corrupted during transmission.

Types of Parity:

   Even Parity: If total number of 1's is even, parity bit=0 otherwise parity bit=1.

   Odd Parity: If total number of 1's is odd, parity bit=0 otherwise parity bit=1.

How it works?

  . Sender and receiver must both agree to use parity checking and also whether it is even or odd.
  . For even, at transmission side, parity generator checks whether total number of 1's are even and adds 0 or 1 accordingly.
  . In receiver side, parity checker checks total number of 1's.
  . If it is matched, data is correctly transmitted.
  . If not, error message is sent or re-transmission of data takes place.