Sample PHP Program

The code inside the box (and the box itself) was written in PHP.

This was written in PHP, but it was coded inside an HTML file with HTML code around it. If you right-click/Inspect, all you'll see is HTML and text, you won't see any actual PHP code(statements, commands, etc.) That's because the PHP code is run on the server and the output of the PHP (plain text and HTML) is sent in the response to the client. So the client only receives plain text and HTML.