When we send ajax request to some php file via post, we get the variables in php file from $_POST, and then send response as a text or html or JSON or whatever with echo or print.
So, what if a lot of such ajax requests come simultaneously? what server does in this case? does it process all of the requests (every request)?
and does it make copies of this php file for each request or does it work with single php file by queueing the requests?