A very basic method of error checking that checks data for errors during a transmission or on a data storage mechanism. Parity works by setting a parity bit to an even or odd number. For example, if the binary stream contains an even amount of 1's and the parity bit is odd, the computer would generate a parity error because the data is corrupt. The picture is an example of an 8-bit binary number with a ninth parity bit and examples of odd and even parity binary with their associated parity bit.
In the past most memory manufacturers had the option between parity and non-parity memory. However, today's computer memory is more reliable and because of costs parity error checking is no longer used. When a memory error does occur with a computer that has no-parity memory it can cause the computer to freeze or generate an error.
Tip: Parity error checking only detects and reports errors, it will not correct the errors found.