What are they used for? I see them used in a few demos/tutorials but I have no idea why people need them. I''m sure there is a good reason though.

There is...example: I made a terrain object that has a lot vertices. I only store the vertices in the array as struct that contains:

the x,y,z of the actual point
the x,y,z of the normal of that point
other info....

surface normals would be to difficult and big to store since I would have to have multiple points for one surface defination.

anyways...
To calculate the vertex normal I take and temporalily make four polyogns around that using other vertexs and I find the average

this gives me a vertex normal.

I can understand why you would think that since a vertex is just a point, but directx and opengl use it for lighting...

I hope that answers the question

"The thing I like about friends in my classes is that they can''t access my private members directly."

Normals are use by 3D API to compute lighting @ vertices.

Wrong normals are the most common source of lighting problems.

Maybe you should learn with books, they explain a lot more than tutorials.
Well of course if you don''t plan to do anything serious (just playing around with code) you don''t need to read books.

Thank you Pactuul! That pretty much does it for me, but I have one more question. The vertex normal coordinates - are they always reletive to the origin? Or are they reletive to the point you are working on? So for a vertex of 10,10,10, would the normal point be ''one'' away from that point, or ''one'' away from 0,0,0? Thanks again!

Normals are vectors, theyre relative to the origin. So with the normal (0,0,1) (remember the z axis goes into the screen), it would point at you, no matter what point in 3d space you give it to.