What is idempotency in service requests?

Idempotency in service requests means that executing the same request multiple times results in the same outcome and does not change the state of the service after the first call.

For example, the HTTP GET method is idempotent because requesting a resource does not change its state, and repeated requests return the same result.

The PUT method is also idempotent because updating a resource with the same data multiple times will not change the result after the first update.

This is important for system reliability, especially in cases of network failures, where a client can repeat a request without the risk of unwanted side effects.