The preceding code is an HTTP POST method, indicated by the [`[HttpPost]`](/aspnet/core/api/microsoft.aspnetcore.mvc.httppostattribute) attribute. The [`[FromBody]`](/aspnet/core/api/microsoft.aspnetcore.mvc.frombodyattribute) attribute tells MVC to get the value of the to-do item from the body of the HTTP request.
The `CreatedAtRoute` method:
* Returns a 201 response. HTTP 201 is the standard response for an HTTP POST method that creates a new resource on the server.
* Adds a Location header to the response. The Location header specifies the URI of the newly created to-do item. See [10.2.2 201 Created](http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html).
* Uses the "GetTodo" named route to create the URL. The "GetTodo" named route is defined in `GetById`:
`Update` is similar to `Create`, but uses HTTP PUT. The response is [204 (No Content)](http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html). According to the HTTP spec, a PUT request requires the client to send the entire updated entity, not just the deltas. To support partial updates, use HTTP PATCH.
![Postman console showing 204 (No Content) response](../../tutorials/first-web-api/_static/pmcput.png)