What is the difference between unset and unlink functions in PHP?

unset() — releases a variable, making it undefined.

<?php

$var = 'some value';
unset($var); // The variable $var no longer exists

unlink() — deletes a file from the filesystem.

<?php

$filename = 'path/to/file.txt';
if (file_exists($filename)) {
    unlink($filename); // Deletes the file path/to/file.txt
}

Main difference: unset() works with variables inside the PHP script, while unlink() works with files on disk.