2-piece wheels
These are the most common wheels and are used by various known brands as Audi, Mini, …
They are called 2-piece wheels because you can disassemble the wheel center from the barrel.
3-piece wheels
This are aftermarket wheels and are almost never used by the car manufacturers. Known brands are BBS, OZ, Ronal, … The wheels consist of a wheel center, an outer rim and an inner rim.