REST

GET = Used to retrieve data identified by the URL - Nullipotent

PUT = Used to set data identified by the URL in an idempotent way - Idempotent

POST = Used to set data identified by the URL in a non-idempotent way - Need not be Idempotent

DELETE = Remove the data identified by the URL - Idempotent

Nullipotent action has no side effects – performing it multiple times is the same as performing it zero times

Idempotent action has no further side effects after the first time performing it – performing it multiple times is the same as performing it one time.