Can PHP run after the page is loaded?

Question

So PHP is executed server-side. But is it possible for PHP to be run after the page is loaded?

To illustrate, if I had a value (stored in a file, lets say) that chan

Answer 1

Your example case is really difficult to explain, without getting technical, or using a lot of chained logic...

...however, I'll try to keep this a little more simple:

The overwhelmingly vast majority of the time, PHP will run only when something connects to the server, and will stop running as soon as it's done running the script that was accessed.

That "something" might be a page-load (//mysite/index.php), or it might be issuing an XMLHttpRequest ("AJAX") to ask the server for data (//mysite/articles.json).

Not all languages work this way.