Can you explain what an HTTP error code means?

The error code in the HTTP protocol is a numeric status that the server returns to the client to indicate the result of processing the request.

Codes are divided into several categories:

• 1xx — informational (e.g., 100 Continue)
• 2xx — successful (e.g., 200 OK)
• 3xx — redirection (e.g., 301 Moved Permanently)
• 4xx — client errors (e.g., 404 Not Found)
• 5xx — server errors (e.g., 500 Internal Server Error)

For example, if a client requests a non-existent page, the server will return 404, which means the resource was not found. This helps the client understand what happened and take appropriate action.