HTTP Methods (Verbs)

In a RESTful API, HTTP methods, often called 'verbs', define the action to be performed on a resource. Using these methods semantically is crucial for creating a clear and predictable API. The primary methods are: 1. **GET**: Used to retrieve data. A GET request should only fetch data and have no other effect (this property is known as 'idempotence' and 'safety'). For example, `GET /users/123` retrieves the user with ID 123. 2. **POST**: Used to create a new resource. A POST request submits data to the server, which then creates a new entity. For example, `POST /users` would create a new user with the data provided in the request body. POST is not idempotent; making the same POST request multiple times will create multiple new resources. 3. **PUT**: Used to update an existing resource completely. A PUT request replaces the entire resource at a specific URI with the data provided in the request body. If the resource doesn't exist, PUT can be configured to create it. For instance, `PUT /users/123` replaces the entire user 123 record. PUT is idempotent; making the same PUT request multiple times has the same effect as making it once. 4. **PATCH**: Used for partial updates to an existing resource. Unlike PUT, PATCH only modifies the fields specified in the request body, leaving other fields unchanged. For example, `PATCH /users/123` could be used to update only the user's email address. 5. **DELETE**: Used to remove a resource. A DELETE request to a specific URI, like `DELETE /users/123`, will delete the user with ID 123. DELETE operations are idempotent. Other less common but useful methods include HEAD (fetches headers without the body), OPTIONS (describes communication options for the target resource), and TRACE (performs a message loop-back test).