i have a beard that is longer than most people
Well, in humans only adult males are typically able to grow beards. So you must be an adult male :D
:) yes I am 
Haha, well it is a vestigial trait from back when humans were covered in hair like gorillas
I always wonder why the face we have a beard when it is not necessary anymore
Yes, it's just leftovers lol. In some cultures, though, beards are associated with poor hygine or being a savage. I wouldn't recommend vacationing in those places.
so which hair grows faster, facial hair or hair on the head?
Funny enough it varies from person to person and if you are balding or not (genetics). Some other cultures (instead of the previous) view beards as central to a man's virility