Hatfield station (HAT) to Norwood Junction (NWD) train with London Public Transportation (3)

Thameslink is a train service that operates in the United Kingdom. It is operated by Govia Thameslink Railway and serves the counties of Bedfordshire, Cambridgeshire, Hertfordshire, London, and Surrey. The trains run from early morning until late at night, with some services running 24 hours a day. There are a variety of train types available, including Class 700 Desiro City, Class 377 Electrostar, Class 387/1 Electrostar, and Class 319/0. Ticket types include Anytime, Off-Peak, Super Off-Peak, and Advance. Onboard facilities include Wi-Fi, power sockets, and air conditioning. The most popular routes for Thameslink are London to Brighton, London to Bedford, and London to Luton.

Great Northern is a train company based in the United Kingdom. It offers a wide range of services, including high-speed trains, regional trains, and sleeper services. The high-speed trains are called InterCity Express Trains and they offer a fast and comfortable journey between major cities. The regional trains are called Regional Express Trains and they provide a slower but more frequent service to smaller towns and villages. The sleeper services are called Caledonian Sleeper Trains and they offer overnight journeys with comfortable sleeping compartments. Great Northern offers a variety of ticket types, including single, return, and group tickets. Onboard facilities include free Wi-Fi, power sockets, and a selection of snacks and drinks. The most popular routes for Great Northern are London to Cambridge, London to Peterborough, and London to Norwich. These routes offer a convenient and comfortable way to travel between the cities.

London Overground is a train company based in the United Kingdom. It operates a network of suburban rail services in and around Greater London. The services run from early morning until late at night, with some lines running 24 hours a day. The trains come in a variety of types, including the Class 378 Capitalstar, Class 172 Turbostar, Class 315, Class 317, Class 508 and Class 700 Desiro City. London Overground offers a range of ticket types, including single, return, off-peak and super off-peak tickets. Onboard facilities include air-conditioning, Wi-Fi, power sockets and CCTV. The most popular routes for London Overground are from Euston to Watford Junction, from Liverpool Street to Enfield Town, and from Clapham Junction to Stratford.

The "Tube" refers to the London Underground, a rapid transit system serving Greater London and parts of the adjacent home counties. It is operated by London Underground Limited (LUL), a wholly-owned subsidiary of Transport for London (TfL). Opened in 1863, it was the world's first underground passenger railway. The network, nicknamed "the Tube" due to its circular, deep-level tunnels, has 11 lines and 270 stations, covering approximately 250 miles. It carries over a billion passengers annually and is known for its iconic roundel symbol and schematic map.