What does 'Gateway' refer to in the 504 Gateway Timeout Meaning?

[datarecovee]

A "gateway" in the 504 Gateway Timeout Meaning is a server which is an intermediary. It accepts your request and sends it to some other server (such as a PHP application server) and waits until you reply. A 504 Error Code will be demonstrated when this gateway server just takes too long to receive that back-end response.