unlink() is used to delete physical files...So lets say you have foo.txt somewhere on your server... unlink(foo.txt) would delete it. unset() is used to null out the value of a given variable. So for instance:
x = 200;
echo(x); // 200
echo(x); // null
The difference between the functions unlink and unset
unlink() is a function for file system handling.
It will simply delete the file in context.
Example for unlink() :
$fh = fopen('test.html', 'a');
fwrite($fh, '<h1>Hello world!</h1>');
unset() is a function for variable management.
It will make a variable undefined.
Unset () is used to destroy a variable in PHP. In can be used to remove a single variable, multiple variables, or an element from an array. It is phrased as Unset ($remove).
Also Known As: Unset Variable, Destroy Variable
Example for unset() :
// remove a single variable
// remove a single element in an array
// remove multiple variables
unset($a, $b, $c);