2S in Indian Railways refers to the second seating class for passengers. It is the lowest reserved class in Indian trains and is also known as the second sitting class. The seats in the 2S class can be joined or may have a little distance between them, and they may or may not possess a cushion. Usually, 2S coaches have seats in a 33 layout, and some 2S coaches can also have a seating arrangement of 32. 2S seats are usually benches and can be booked online. A 2S seat in a train will not offer sleeping facilities as it is only for seating, and it is a good option for a short (4-5 hours) journey. One should not confuse 2S class with the general coaches on Indian trains. 2S class is a reserved section, and you have to pre-book your seat in 2S class. If you have booked a 2S seat in a train, you will get a dedicated seat number, and only you are authorized to sit in your 2S seat in the train as it is reserved.