The Skytrain BTS is one of the currently two public mass transport systems in Bangkok, the other is the MRT Subway. There are to date two BTS lines, the Sukhumvit and Silom line (sometimes also referred as light green and dark green line). Please note something important: The local Thai people use only the term BTS, not Skytrain. Therefore, when asking or talking about BTS stations or directions, then people might understand what you are talking about and can help you. Another hint, the pronunciation in Thai-English for BTS sounds more like B-T-at because in the Thai alphabet there is no sound for an “s” at the end of a word.
Back to the use of the BTS system, it is relatively inexpensive and in the always gridlocked traffic of Bangkok a quick and comfortable way to get around in the city. Every station consists of two levels (except the interchange station Siam has three levels). The first level is equipped with ticket machines as well as ticket and information counters. You can also change your bills to coins to use them at one of the machines, though some newer machines also now accept bills. The ticket machines have a touchscreen where you can choose your desired destination and it shows you the fare. The single journey ticket is a credit-card sized ticket, that you have to swipe or touch at the entry and at the exit insert it into the slot.
You can take either stairs or escalators to the second concourse level. Be careful to take the correct side / direction. Besides the already mentioned single journey ticket, there are another alternatives, a one-day pass and a stored-value ticket called “Rabbit Card”. If you are planning to stay few days in Bangkok and using the BTS from the hotels near Ploenchit station to explore the city, we strongly recommend you to buy a Rabbit Card. It will save you time and nerves because you don't have to queue up to change bills and buy a ticket.
Lastly, some information about the important stations of each line. Siam station is the interchange station between the Silom and Sukhumvit line. The northern terminal station Mo Chit can connect with the MRT subway at their station Chatuchak Park. Same goes for Asok (BTS) — Sukhumvit (MRT) and Saladaeng (BTS) — Silom (MRT) stations. At the Phaya Thai BTS station there is a connection to the ARL Airport Rail Link station with the same name. Another BTS station of interest to tourists might be Saphan Taksin, because from there you can connect to the boats and water taxis on the Chao Phraya river. And did you know that the Lohas Residences Sukhumvit Hotel is in walking distance from BTS Phloenchit and BTS Nana Stations? Therefore it is ideally located for any activity in the lively city of Bangkok.