A certain train car is a type of rail car that is used on passenger trains. It typically consists of a SLEEPER, a DINER, and a SMOKER. A SLEEPER is a type of rail car that contains sleeping compartments for passengers to rest in during long trips. A DINER is a rail car that contains a restaurant-style kitchen and seating area for passengers to enjoy meals. Finally, a SMOKER is a rail car that contains a designated area for passengers to smoke.