The drivetrain is made up of the crank arms, chain rings, bottom bracket, front derailleur, chain, your rear derailleur and free wheel or cassette.
All the car's parts that make it move including the engine, transmission, differential, hub, shafts, etc.
Components used to propel the vehicle. It delivers power from the engine to the drive wheels. In rear-wheel drive vehicles, the drivetrain includes the engine, clutch, transmission, driveshaft, differential and rear axle shafts.