First class car has 9 compartments (coupe), for 2 persons each. In a compartment, there are 2 berths to sit or lie on, and a table between. Luggage can be placed under berths. Compartment door can be closed. At each end of every car there is a bathroom with WC and water basin. First class in a seating car (usually in express trains) has a table and extended room for legs. Seats rows are nearly the same as in an airplane.
Second class car, kupeiny vagon. The difference with the first class is that there are 4 berths instead of 2: two lower and two upper ones. Luggage can be placed under lower berths and to the compartment above the door. The door can be locked. By the window, there is a table. Each car also has two bathrooms. 36 people can travel in such a car at the same time.
The second class in a seating car does not have tables; seats rows are nearly the same as in an airplane.
In a third class car, 54 persons can travel at the same time. Compartments in such cars are open, there are 4 berths in each plus 2 berths over the corridor. Luggage can be placed under lower berths and on 3rd berths, specially designed to store luggage. Travelling in the third class is less comfortable than in the 1st and 2nd classes, but much cheaper.