How does antibacterial hand soap work?!

I'm no expert but here's a mini Science lesson for you.

Germs or 'bacteria' are often picked up on your hands, then transferred to inside you (in a variety of ways, including preparing food without washing them).
This means that washing your hands is one of the best spots to target germs.
The chances are, the soap contains little things called 'antibodies', these are developed organisms which are designed to kill specific germs. This is the way some vaccines work.
The soap probably contains a variety of these antibodies, as will anti-bacterial household cleaners and the like.
I'd go in to more detail, but right now I can't be bothered.
If you'd like more info... google 'how do antibodies work' :)