Some surface questions

Can someone explain me this: when I create (or load) a mesh, how are surfaces envolved?
I understood that if you have many surfaces, your game will have low fps.
Can 2 meshes share the same surface, like 2 speheres that are like this: one is half red, half white, the other is half red, half black, and the red half of both be on one surface?
Thankx!

Each mesh can have many surfaces (but must have at least one). Meshes can't share surfaces, but if the meshes don't move you can create code to combine similar colored/textured ones into one surface.

The fewer the surfaces the faster your game.