The T subway is a rapid transit system serving the Greater Boston area in Massachusetts. Operated by the Massachusetts Bay Transportation Authority (MBTA), it consists of four main lines: the Red Line, Orange Line, Blue Line, and Green Line. The system provides an efficient way for residents and visitors to navigate the city and its suburbs. The T subway features a mix of underground and above-ground tracks, with numerous stations that connect to bus and commuter rail services. It is a vital part of Boston's public transportation network, helping to reduce traffic congestion and promote sustainable travel options.