# Parity Check

## Definition - What does Parity Check mean?

A parity check is the process that ensures accurate data transmission between nodes during communication. A parity bit is appended to the original data bits to create an even or odd bit number; the number of bits with value one. The source then transmits this data via a link, and bits are checked and verified at the destination. Data is considered accurate if the number of bits (even or odd) matches the number transmitted from the source.

## Techopedia explains Parity Check

Parity checking, which was created to eliminate data communication errors, is a simple method of network data verification and has an easy and understandable working mechanism.

As an example, if the original data is 1010001, there are three 1s. When even parity checking is used, a parity bit with value 1 is added to the data’s left side to make the number of 1s even; transmitted data becomes 11010001. However, if odd parity checking is used, then parity bit value is zero; 01010001.

If the original data contains an even number of 1s (1101001), then parity bit of value 1 is added to the data’s left side to make the number of 1s odd, if odd parity checking is used and data transmitted becomes 11101001. In case data is transmitted incorrectly, the parity bit value becomes incorrect; thus, indicating error has occurred during transmission.