HTTP Status Code

HTTP STATUS CODE- 

200 OK- The request has succeeded. The meaning of the success depends on the HTTP method:
GET: The resource has been fetched and is transmitted in the message body.
HEAD: The entity headers are in the 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.

201 Created- The request has succeeded and a new resource has been created as a result. This is typically the response sent after POST requests, or some PUT requests.

202 Accepted - The request has been received but not yet acted upon. It is noncommittal, since there is no way in HTTP to later send an asynchronous response indicating the outcome of the request. It is intended for cases where another process or server handles the request, or for batch processing.

204 No Content- There is no content to send for this request, but the headers may be useful. The user-agent may update its cached headers for this resource with the new ones.

Redirection messages--

300 Multiple Choice- The request has more than one possible response. The user-agent or user should choose one of them. 

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

302 Found- This response code means that the URI of requested resource has been changed temporarily. Further changes in the URI might be made in the future. Therefore, this same URI should be used by the client in future requests.

Client error responses-

400 Bad Request-The server could not understand the request due to invalid syntax.

401 Unauthorized- Although the HTTP standard specifies "unauthorized", semantically this response means "unauthenticated". That is, the client must authenticate itself to get the requested response.

403 Forbidden-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, the client's identity is known to the server.

404 Not Found- The server can not 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 to hide the existence of a resource from an unauthorized client. 

405 Method Not Allowed- The request method is known by the server but has been disabled and cannot be used.

Server error responses-

500 Internal Server Error- The server has encountered a situation it doesn't know how to handle.

501 Not implemented- The request method is not supported by the server and cannot be handled. The only methods that servers are required to support (and therefore that must not return this code) are GET and HEAD.

502 Bad Gateway- This error response means that the server, while working as a gateway to get a response needed to handle the request, got an invalid response.

503 Service Unavailable -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. T

504 Gateway Timeout - This error response is given when the server is acting as a gateway and cannot get a response in time.

505 HTTP Version Not Supported -The HTTP version used in the request is not supported by the server.