Answer 1

No, you need to include or require for a php file.

so,

<?php
include('path/to/my/file.php');

or

require_once('path/to/my/file.php');

?>

The difference between include and require is, include will continue to execute the script regardless of errors, where as require will exit and terminate the process if it encounters and error.

For example, if the php file your including has 5 functions and the 3rd function has an error within it, then function 1,2,4,5 will still be executed. Where as require will only execute 1,2.

Hope this helps.