This guide helps you understand the different HTTP status codes.

1xx - Informational

Error 100: Continue
 The server has received the request headers, and the client can continue sending the request body.
 
Error 101: Protocol Change
 The server agrees to change the communication protocol as requested by the client.

2xx - Success

Error 200: Request succeeded
 The request has been successfully processed by the server.

Error 201: Document Created (reason: new URI)
 The request has succeeded and resulted in the creation of a new resource.

Error 202: Request Accepted for Async Processing (TBS)
 The request has been accepted, but the processing is not yet complete.

Error 203: Non-Authoritative Information
 The server successfully processed the request, but the returned information comes from a third-party source.

Error 204: No Content
 The request has been successfully processed, but there is no content to return.

Error 205: Reset Content
 The server has successfully processed the request and requests the client to reset the document that submitted the request.

Error 206: Partial Content
 The server is returning only part of the data, as requested by the client with the `Range` header.

3xx - Redirections

Error 300: Multiple Choices
 The request has multiple possible responses, and the server cannot automatically choose one of them.

Error 301: Moved Permanently
 The requested resource has been permanently moved to a new URL.

Error 302: Found (Moved Temporarily)
 The requested resource is temporarily located at another URL.

Error 303: See Other
 The response to the request can be found under a different URL using the GET method.

Error 304: Not Modified
 The resource has not been modified since the last request. No new data will be returned.

Error 305: Use Proxy
 The requested resource must be accessed through the proxy specified by the server.

Error 307: Temporary Redirect
 The requested resource resides temporarily under a different URL, but the client must use the same method for the next request.

4xx - Client Errors

Error 400: Bad Request
 The request is invalid or malformed.

Error 401: Unauthorized
 Access to the resource requires authentication.

Error 402: Payment Required
 This code is reserved for future use regarding online payments.

Error 403: Forbidden
 The server understands the request but refuses to authorize it.

Error 404: Not Found
 The server cannot find the requested resource.

Error 405: Method Not Allowed
 The method specified in the request is not allowed for the resource.

Error 406: Not Acceptable
 The requested resource is not capable of generating acceptable content according to the `Accept` headers sent in the request.

Error 407: Proxy Authentication Required
 Access to the resource requires authentication by a proxy.

Error 408: Request Timeout
 The server did not receive a complete request within the time limit.

Error 409: Conflict
 The request cannot be processed due to a conflict with the current state of the resource.

Error 410: Gone
 The requested resource is no longer available and will not be available again.

Error 411: Length Required
 The server refuses to process the request without a valid `Content-Length` header.

Error 412: Precondition Failed
 One of the conditions specified in the request headers has failed.

Error 413: Payload Too Large
 The server refuses to process the request because the size of the payload is too large.

Error 414: URI Too Long
 The server refuses to process the request because the URI is too long.

Error 415: Unsupported Media Type
 The server refuses to process the request because the format of the request entity is not supported.

5xx - Server Errors

Error 500: Internal Server Error
 The server encountered an unexpected condition that prevents it from fulfilling the request.

Error 501: Not Implemented
 The server does not support the functionality required to fulfill the request.

Error 502: Bad Gateway
 The server, acting as a gateway or proxy, received an invalid response from the upstream server.

Error 503: Service Unavailable
 The server is currently unavailable (overloaded or in maintenance).

Error 504: Gateway Timeout
 The server, acting as a gateway or proxy, did not receive a timely response from the upstream server.

Error 505: HTTP Version Not Supported
 The server does not support the HTTP protocol version used in the request.