This document provides terms and definitions for rail networks and rail vehicles guided by track and wheels, both made of steel and/or other materials. This includes heavy rail and urban rail systems. This document is applicable as a reference for future European Standards and the revision of existing standards and represents a set of general technical terms and definitions. This document does not apply to specific applications such as: - track construction and maintenance machines not travelling on rails; - road-rail machines when not travelling on rails; - magnetic levitation transport networks and vehicles; - guided busways and guided busses; - non-public rail networks and vehicles, e.g. mine rail systems; - rail networks and vehicles exclusively for leisure, historical and tourist purposes, e.g. mountain-, field-, park-, cable rail systems, funiculars and theme park rides; - trolley busses. Not in the scope are terms and definitions related to: - control command and signalling, - operation, - geographical aspects.