computer graphics for java

HI,
Im a newbie to computer graphics and was wondering about a bunch of stuff I need to ask about.
There is a thing called orientation of 3 points. in the xy -plane. counter clockwise or clockwise((positive and negative). What is this I dont understand what it is and why we would need to the the orientation of 3 points on a plane when we visit each point.
To determine the orientation of a point
a = a1 + a2j + 0K
b=b1 + b2j + 0k
and axb is (a1b2 - a2b1)K

sorry if this sound stupid but Im trying!!! hehe
so if a=b is > 0 are we talking the right hand rule for the k vector???

For flash, but it seems to explain backface culling fairly accurately:

http://www.kirupa.com/developer/actionscript/backface_culling.htm

Hi,
Thanks !!! This is very helpful. The site seems really good also.
Thanks again.