What is Idempotence? Explained with Real-World Examples

Idempotence is a property of an operation that ensures that, if the operation is repeated once or more than once, you get the same result. It is used in both the physical world and software architectures to build reliable and fault-tolerant systems. Examples of idempotence include traffic light buttons and elevator call buttons. In software architectures, HTTP methods like GET, HEAD, PUT, and DELETE are inherently idempotent. The Post/Redirect/Get pattern is a way to make a POST operation idempotent.