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Great Western Railway (GWR) is a British railway company that operates passenger services between London and the southwest of England, as well as parts of Wales. It was founded in 1833 and was originally known as the Great Western Railway Company. GWR is now owned by FirstGroup. The company is known for its iconic green livery and its historic steam locomotives, including the famous Flying Scotsman.

London Overground is a suburban rail network in London, England. It was created in 2007 by the merger of the former Silverlink Metro service with other rail services. The network consists of 112 stations and serves 23 London boroughs. London Overground operates on these routes, which include Highbury & Islington to West Croydon/Clapham Junction/Crystal Palace, Richmond/Clapham Junction to Stratford, Gospel Oak to Barking Riverside, Watford Junction to Euston, Liverpool Street to Enfield Town/Cheshunt, Liverpool Street to Chingford, and Romford to Upminster. Overground is operated by Arriva Rail London under a concession from Transport for London.

The London Underground, also known as "the Tube", is a rapid transit system that serves London and some parts of the surrounding counties. It is the oldest underground railway network in the world, with the first line opening in 1863. The Tube is a vital part of London's transportation infrastructure, carrying over five million passengers per day. It is operated by Transport for London (TfL) and is known for its iconic map, distinctive roundel logo, and deep-level tunnels.

South Western Railway (SWR) is a train operating company in the United Kingdom that operates passenger services in South West England and parts of Southern England. It was formed in 2017 as a result of the merger of South West Trains and the Island Line Trains. SWR operates services to major cities such as London, Bristol, Southampton, and Portsmouth, as well as smaller towns and villages in the region. The company operates a fleet of modern trains, including electric and diesel multiple units, and provides a range of ticketing options, including season tickets, advance purchase tickets, and flexible fares. SWR is owned by FirstGroup and MTR Corporation.

West Midlands Trains is a train operating company. The company is operated by a joint venture between Abellio, JR East, and Mitsui and runs under a franchise agreement with the Department for Transport. West Midlands Trains operates a fleet of over 400 trains, serving over 150 stations across the region, including Birmingham, Coventry, Wolverhampton, and Stoke-on-Trent. The firm provides a variety of services, including long-distance trips to places like London and Liverpool as well as local and regional trains.

National Rail is a network of railway companies that operate in England, Scotland, and Wales. It encompasses a network of train operators, including Train Operating Companies, open access operators, freight operating companies, and Network Rail. National Rail is managed and supported by the Rail Delivery Group (RDG), which provides essential business services to ensure the smooth operation and coordination of the railway industry.