Now, PHP is a so-called server-side language, which makes it different from languages like JavaScript.

Why might that be?

Any PHP script needs to run on a serverOnly the results of a script are displayed in the browserAny PHP script can run in a browser

That's it! PHP scripts run on a server, which is the computer that stores them. Only the results are delivered to browser.

Could it be that a server-side language can't run on a client-side browser?