Line A (Rome Metro) in the context of Battistini (Rome Metro)

Line B is a metro line serving Rome, Italy, and part of the Rome Metro. Despite its name, Line B was the first line to be built in the city. It crosses Rome diagonally from north-east, starting at Rebibbia and at Jonio stations, to south, terminating at Laurentina, in the EUR district. It crosses Line A at Termini station. The line has 26 stations and is shown in blue on Metro maps.

The Rome Metro (Italian: Metropolitana di Roma) is a rapid transit system that operates in Rome, Italy. It started operation in 1955, making it the oldest in the country.

The Metro comprises three lines – A (orange), B (blue) and C (green) – which operate on 60 km (37 mi) of route, serving 73 stations. It has a daily ridership of approximately 820,000 passengers, and an annual traffic of approximately 320 million passengers.

Termini is an underground station of the Rome Metro. The station was inaugurated on 10 February 1955 as a station on Line B, and later became an interchange with Line A when service on that line began in February 1980. A major renovation of the station's interchange nodes and atrium was completed in 2013 to improve passenger flow and accessibility. The station is found in Piazza dei Cinquecento, under the Termini rail terminal. Together, the two stations form the main public transport hub in the city.

Termini is currently the only station in the Rome Metro system to serve both Lines A and B.

Line C is a Rome Metro line which runs from Monte Compatri-Pantano in the eastern suburbs of Rome, in Italy, to a temporary terminus at Colosseo. It is the third metro line to be built in the city and the first to be fully automated.

The line has interchanges with two other Metro lines: one with Line B at Colosseo and one at San Giovanni where it meets Line A.