Because trucks are so big and heavy, their brake rotors are especially important brake parts.
It takes a lot of force to stop a truck. Slowing down or stopping a heavy vehicle requires, among other factors, a lot of friction from the brakes. The friction between the brake pads and the brake rotors generates a lot of heat, too. The extra weight and heat means that the rotors in a large truck are under a lot more stress than they would be in a smaller vehicle.
Even with the extra stresses truck brake rotors are under, they're still largely the same as the ones used on cars and smaller trucks. Truck brake rotors tend to be made of cast iron or steel, and they're typically much larger than the brake rotors found on cars. However, truck rotors may require service more often than car rotors. That's not because the rotors themselves don't last, but rather, due to the extra stress of stopping a truck, the truck's brake pads tend to wear out more quickly. If worn brake pads aren't changed early enough, they can cause damage to the brake rotors. Worn pads can scratch or even warp the rotors to the point where they need to be either machined to a new smooth surface or replaced. While this can (and does) happen on cars too, it tends to happen more frequently on heavy trucks because their brake pads tend to wear out sooner.
Read the next section to find out the brake part that makes all the difference to high performance drivers on the street and on the track.