The Yamanote Line (山手線, Yamanote-sen?) is a railway loop line in Tokyo, Japan, operated by East Japan Railway Company (JR East). It is one of Tokyo's busiest and most important lines, connecting most of Tokyo's major stations and urban centres, including the Yūrakuchō/Ginza area, Shibuya, Shinjuku, and Ikebukuro, with all but two of its 29 stations connecting to other railway or underground (subway) lines.
The "Yamanote Line" as an official line name indicates the tracks between Shinagawa and Tabata that is used by local trains on their own tracks as well as the parallel Yamanote Freight Line which is used by Saikyō Line and Shōnan-Shinjuku Line trains, some limited express services, and freight trains. However, in everyday usage the "Yamanote Line" refers to the entire 34.5 km loop line served by local trains. (This article uses the same definition.)
East Japan Railway Company (東日本旅客鉄道株式会社, Higashi-Nihon Ryokaku Tetsudō Kabushiki-gaisha?) is the largest passenger railway company in the world and one of the seven Japan Railways Group companies. The company name is officially abbreviated as JR East in English, and as JR Higashi-Nihon (JR東日本?) in Japanese. The company's headquarters are in Yoyogi, Shibuya, Tokyo.