As the title implies, What are they? i see a set in the market that has them, but i wanna know what they are or do that are better than any other texture.

It add some 3D effetcs in texture, like shadows and lights, dl and lp me to you see.

Moved to Beginner Sanctuary.

Yep. They just add a more physical texturing effect. If you want guides you can google them. There's also a wiki page on it with more info.