You can also create references to subroutines, among other things.
Creating a reference to a predefined subroutine
# define the subroutine
sub foo {
print "Hello from foo()\n";
}
# the \ prefix means "address of" to create a reference
my $reference = \&foo;
# the & de-references the $reference variable, and the subroutine is executed
&$reference();