title: Parity
text: # Parity
  
  Parity may refer to:
  
  * Parity (computing)
     * Parity bit in computing, sets the parity of data for the purpose of error detection
     * Parity flag in computing, indicates if the number of set bits is odd or even in the binary representation of the result of the last operation
     * Parity file in data processing, created in conjunction with data files and used to check data integrity and assist in data recovery
  * Parity (mathematics), indicates whether a number is even or odd
     * Parity of a permutation, indicates whether a permutation has an even or odd number of inversions
     * Parity function, a Boolean function whose value is 1 if the input vector has an odd number of ones
     * Parity learning, a problem in machine learning
     * Parity of even and odd functions
  * Parity (physics), a symmetry property of physical quantities or processes under spatial inversion
  * Parity (biology), the number of times a female has given birth; gravidity and parity represent pregnancy and viability, respectively
  * Parity (charity), UK equal rights organisation
  * Parity (law), legal principle
  * Mental Health Parity Act, also applies to substance use disorder
  * Purchasing power parity, in economics, the exchange rate required to equalise the purchasing power of different currencies
  * Interest rate parity, in finance, the notion that the differential in interest rates between two countries is equal to the differential between the forward exchange rate and the spot exchange rate
  * Put–call parity, in financial mathematics, defines a relationship between the price of a European call option and a European put option
  * Parity (sports), an equal playing field for all participants, regardless of their economic circumstances
  * Potty parity, equalization of waiting times for males and females in restroom queues
  * A tactic in reversi
  * Grid parity of renewable energy
  * Doctrine of parity, agricultural price controls
  * Military parity, equipotential readiness between foes, without gaps such as a missile gap
  * Special cases in combination puzzles
  