M5 Tracktool answered perfectly, here is just a little additional information since I am not sure what you are looking for as your question was a little more general....
most cars have composite brakes. You look at the pad and you can get metallic, semi-metallic, ceramic, etc. They essentially are the same materials, in different proportions. The rotors typically have a thin layer of steel around the surface, and lighter alloys inside in order to reduce rotating mass (which is absolutely critical to performance such as accelerating & braking, more so then weight, torque and horsepower). Some high-end cars have carbon ceramic brake rotors. These significantly reduce the rotating mass of the rotor, allow more consistent braking (less brake fade), require zero maintenance (per manufacturer's claims, they last the lifetime of the vehicle), and allow higher braking temperatures. The draw back is that they are very, very expensive. You will find them standard (or factory option) on Ferrari, Porsche, Aston Martin, and oddly enough Corvette ZR-1 to name a few. The last time I shopped at Porsche, the option to upgrade from Porsche 911 Turbo brakes to the Porsche Ceramic Composite Brake rotors was $8800 (keep in mind that is an upgrade price + the cost of the traditional brakes). The brakes designed for the Nissan GT-R Spec V for example cost $50,000 for a set of 4. On the track, I have driven with ceramic rotors and the later day events after 5 or 6 races on a hot summer day... the car stops just as though it was the first time you touched the pedal. However the overwhelming majority of people use standard rotors because of the cost. I was looking for a set for our M6, but the only company I have seen that offered ceramic rotors was G-Power, and they never replied to my inquiry.
