Which of the following describes a RESTful service's PUT method?

The PUT method in a RESTful service is designed specifically for updating an existing resource on the server. This method sends data to the server to modify the resource identified by the given URL. When a client issues a PUT request, it typically includes the updated representation of the resource in the request body, and the server uses this data to replace the current state of that resource.

In the context of RESTful principles, this aligns with the notion of idempotence, which means that multiple identical requests should have the same effect as a single request. In other words, sending the same PUT request multiple times will not change the outcome beyond the initial application.

This is distinct from creating a new resource, which is accomplished using the POST method, or retrieving data, which is done with the GET method. Likewise, the operation of deleting a resource is associated with the DELETE method. Understanding these distinctions is crucial for effective RESTful service design and usage, allowing for proper implementation of CRUD (Create, Read, Update, Delete) operations.