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

PHP is server-side script, before return page content to client side like browser, it should parse all the PHP logic into HTML logic, so it should display the value which was at page load. And if your PHP logic consumes long time to execute, it will delay the content display at client side.