why shift @_ ?

[david wright]

I have seen Ex #1 "corrected" (as being more well written) to Ex #2. In 
this case it is just being passed a $ but the data being passed was 
irrelevant. (though not a ref) I still don't see why, i guess i don't 
fully understand "shift". Any light shedder's appreciated, thanks : -)

EX #1:
sub makeArray{
my @array = @_;
         foreach(@array){
         print $_  . "\n";
          }
   }


Ex #2
sub makeArray{
my @array = shift @_;
         foreach(@array){
         print $_  . "\n";
          }
   }