• Indexed by key name
• An index in curly braces refers to a hash item
• Each item is a scalar, so use scalar syntax $hash{$key}
• Items are stored in random order
• Looking up items is faster than searching through an array
• Can directly assign a hash item

        print "A bicycle has $wheels{bike} wheels.\n";              

        $wheels{bike} = 4; # Adds training wheels 
        print "A bicycle with training wheels has $wheels{bike} wheels.\n";
      

        Output:
        A bicycle has 2 wheels.
        A bicycle with training wheels has 4 wheels.