Success, and the resource was created.

The client does not have access rights to the content; that is, it is unauthorized, so the server is refusing to give the requested resource. Unlike 401 Unauthorized, the client's identity is known to the server.

This response is sent when the requested content has been permanently deleted from server, with no forwarding address. Clients are expected to remove their caches and links to the resource. The HTTP specification intends this status code to be used for "limited-time, promotional services". APIs should not feel compelled to indicate resources that have been deleted with this status code.

The server has encountered a situation it does not know how to handle.

The URL of the requested resource has been changed permanently. The new URL is given in the response.

The server successfully processed the request and is not returning any content.

The server cannot find the requested resource. In the browser, this means the URL is not recognized. In an API, this can also mean that the endpoint is valid but the resource itself does not exist. Servers may also send this response instead of 403 Forbidden to hide the existence of a resource from an unauthorized client. This response code is probably the most well known due to its frequent occurrence on the web.

This is used for caching purposes. It tells the client that the response has not been modified, so the client can continue to use the same cached version of the response.

The request succeeded. The result meaning of "success" depends on the HTTP method:

• GET: The resource has been fetched and transmitted in the message body.
• HEAD: The representation headers are included in the response without any message body.
• PUT or POST: The resource describing the result of the action is transmitted in the message body.
• TRACE: The message body contains the request message as received by the server.

The server is not ready to handle the request. Common causes are a server that is down for maintenance or that is overloaded. Note that together with this response, a user-friendly page explaining the problem should be sent. This response should be used for temporary conditions and the Retry-After HTTP header should, if possible, contain the estimated time before the recovery of the service. The webmaster must also take care about the caching-related headers that are sent along with this response, as these temporary condition responses should usually not be cached.

A temporary redirect.

The client request has not been completed because it lacks valid authentication credentials for the requested resource.

The server understands the content type of the request entity, and the syntax of the request entity is correct, but it was unable to process the contained instructions