The each() function is used to retrieve the next key/ value pair from a hash if its used in a list context , if called in a scalar context only the next key of the hash is retreived.

    each hash; 

    #! C:\programfiles\perl\bin\perl
    print "content-type: text/html\n\n";
    %color = ('1' => 'Green' , '2' => 'Orange', 
       '3' => 'Blue', '4' => 'Pink');
    while (($key, $value) = each %color)
    {
     print "$key=$value\n";
    }

    4=Pink 1=Green 3=Blue 2=Orange

In the above example using the each() function every time in a loop a key, value pair is fetched and displayed. As you can see that the pairs returned are random and not in the same order as they are in a hash.