i have been watching some videos on youtube basically watching various people playing especially in the streets of spain among other places and i notice that other than the rhythm that is unique to the spanish culture is that they use the back of the finger nail to get the sound. my question is does it matter what way you use to play a flamenco song as long as the rhythm and the sound is achieved
Flamenco incorporates several techniques that contribute to the overall sound. So yes, it does matter, because otherwise you probably won't be able to duplicate the sound and rhythm.

For example, there's no way you will be able to duplicate rasgueado without employing a rasgueado technique. As far as I know, at least.

Lumped together, the answers to your questions so far are:

-flamenco is played with your fingers
-it's a very demanding style that incorporates several techniques, many of which are exclusive to the style
ok kool i'm fasinated by the rumba technique and trying to find out as much as i can about it