PHP is probably the only language in which you can't start writing code right away. Such code will be perceived by the interpreter (the program executing the code) as plain text. Any PHP code should be wrapped in a `<?php ?>` construct.

`<?php` is the opening tag and `?>` is the closing tag. PHP allows you to omit the closing part `?>`. And the PSR-12 code manual doesn't let you include it at all.
