A "Server Error" occurs when a web server encounters an issue that prevents it from fulfilling a request made by a user. This can happen for various reasons, such as misconfigurations, overloaded servers, or software bugs. Common server error codes include 500 Internal Server Error and 502 Bad Gateway, which indicate that something went wrong on the server side. When users experience a server error, they may see a message indicating the problem, but it often does not provide specific details. These errors can disrupt access to websites and online services, leading to frustration for users and potential loss of business for website owners.