Updating the contents of a resource is done using the PUT method. The content provided in the request is supposed to be stored under the supplied resource. To delete a resource, the DELETE method is used.
The PUT and DELETE methods, together with the GET and HEAD methods, are considered idempotent. This means that any number of identical requests made to the server, in sequence, results in the same server or resource state. This property is used by caches in clients, web proxies, and the server itself, to optimize performance. For idempotent method calls, cached responses can be returned.
An idempotent operation I(x) is such that In(x)=I(x) for all n∈ℤ+.