Master the standard response codes. Visualizing success, redirection, client errors, and server failures.
The request succeeded. The result depends on the HTTP method (GET, POST, etc.).
The request succeeded, and a new resource was created. Typically the result of a POST.
The server successfully processed the request, but is not returning any content (common in DELETE).
The URL of the requested resource has been changed permanently. The new URL is given in the response.
Indicates the resource has not been modified since the version specified by the request headers (Caching).
The server cannot or will not process the request due to something that is perceived to be a client error.
Authentication is required and has failed or has not been yet provided.
The client does not have access rights to the content; unlike 401, the client's identity is known.
The server can not find the requested resource. The URL is likely incorrect.
The user has sent too many requests in a given amount of time (Rate Limiting).
The server has encountered a situation it does not know how to handle.
The server, while acting as a gateway or proxy, received an invalid response from the upstream server.
The server is not ready to handle the request. Common causes are a server that is down for maintenance or is overloaded.