Berlin is known for its efficient and comprehensive public transportation system. The city's network includes the U-Bahn (underground/subway), S-Bahn (suburban trains), trams, buses and ferries. Tickets can be purchased at ticket machines in stations, online or via mobile apps. Prices vary depending on the zone and duration of the ticket. It's important to validate your ticket before use, especially on trams and buses, where ticket machines are available on board. The city is divided into three fare zones: A, B, and C. Zone A includes the city center, Zone B covers the area outside the center, and Zone C extends out to the city limits. For tourists, the 'Berlin WelcomeCard' is a popular choice, offering unlimited travel within the chosen zones and discounts for many attractions.