5xx status codes refer to the HTTP (Hypertext Transfer Protocol) status codes that indicate that there was an error on the server side when processing the request from the client. These status codes indicate that the server could not fulfill the request, even though the request was valid and well-formed.
Standard 5xx status codes are:
500 Internal Server Error: The server encountered an unexpected condition that prevented it from fulfilling the request. This can happen when there is a problem with the server-side code, or the server cannot access a required resource.
503 Service Unavailable: The server is temporarily unable to handle the request due to a temporary overloading or maintenance of the server.
Other 5xx status codes are:
501 Not Implemented: The server does not support the functionality required to fulfill the request.
502 Bad Gateway: The server received an invalid response from an upstream server while trying to fulfill the request.
504 Gateway Timeout: The server did not receive a timely response from an upstream server while trying to fulfill the request.
5xx status codes indicate an issue on the server side, and the request cannot be fulfilled. These errors can occur due to various issues, such as server overload, software bugs, or misconfigurations. Website owners and webmasters should monitor these status codes, as they can indicate problems with the server or the website’s code, and should take steps to troubleshoot and resolve the issues.
Also, See: 4xx Status Codes