Named subroutine definitions are global--no matter where you put them in your code. On the other hand, anonymous subroutines (i.e. closures) can see the variables in the scope in which they are defined:

my @coderefs;

for my $num (10, 20, 30) {

    my $ref = sub {print "$num\n"};

    push @coderefs, $ref;

} 

#Note: $num has ceased to exist here...

#...yet the following subs can still see the value of 
#$num at the time they were created:

$coderefs[0]->();
$coderefs[2]->();


--output:--
10
30
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