parity

In economics, equality of price, rate of exchange, wages, and buying power. Parity ratios may be used in the setting of wages to establish similar status to different work groups. Parity in international exchange rates means that those on a par with each other share similar buying power. In the USA, agricultural output prices are regulated by a parity system.

parity

Of a number, the state of being either even or odd. In computing, the term refers to the number of 1s in the binary codes used to represent data. A binary representation has even parity if it contains an even number of 1s and odd parity if it contains an odd number of 1s.

For example, the binary code 1000001, commonly used to represent the character ‘A’, has even parity because it contains two 1s, and the binary code 1000011, commonly used to represent the character ‘C’, has odd parity because it contains three 1s. A parity bit (0 or 1) is sometimes added to each binary representation to give all the same parity so that a validation check can be carried out each time data are transferred from one part of the computer to another. So, for example, the codes 1000001 and 1000011 could have parity bits added and become 01000001 and 11000011, both with even parity. If any bit in these codes should be altered in the course of processing the parity would change and the error would be quickly detected.