Can you please explain to me what
a) vertices
b) poligons
c) normals
d) vertixes.
I mean, I know how to use half of this staff, but what’s their technical definition? Because to me they are tools of blender, which obviously is wrong.
vertex : one point in 3d space
edge: a line connecting two vertices
Face: polygon with three or four edges/vertices
Polygon: a closed figure with three or more straight sides
Normal: Think of a normal as a line coming straight out of a face. To make normals visible in blender try the following:
Make a cube, press tab to go in editmode, press F9, in the right Mesh Tools 1 panel you’ll find a button Draw Normals to switch normals on.
You find all these basic things and much more in the blender documentation. A good introduction can also be found in the 3 pfd documents (each about 3 MB) at the following link:
http://www.statikonline.com/Blender/
Thx! You guys are awesome 
well a bit more precise about normals:
they’re the direction a face is facing. if you imaging surface (your arm), how does a 3d program know, if the surface is outside or inside (like in a tunnel)? so that’s why you have normals.
a bunch of stuff is affected by the normals; like the light reflection. you can fake a bumpy surface by tweaking the normals facing another direction. this is achieved trough a bumpmap (the nor button in the mapto buttons (material)).