sub some_function
{
   my ($first, $second) = @_;

   ...
}

sub some_method
{
   my ($self, $first, $second) = @_;

   ...
}

##</code><code>##

SomeClass->some_method( $first, $second );

$some_object->some_method( $first, $second );

##</code><code>##

package SomeClass;

sub new
{
    my $class = shift;
    bless {}, $class;
}

...

my $some_object = SomeClass->new();