Rail transport company in the context of "Turkish State Railways"

A railway infrastructure manager is a rail transport company or body of other type, responsible for maintaining railway infrastructure. The European Union defines it as "any body or undertaking that is responsible in particular for establishing and maintaining railway infrastructure. This may also include the management of infrastructure control and safety systems. The functions of the infrastructure manager on a network or part of a network may be allocated to different bodies or undertakings" This includes mainly railway track and catenary, if the railway line is electrified, and respective command and control systems. It can also include the stations and power supply network. A significant proportion of these companies are state-owned monopolies, responsible for all or most of the railway infrastructure within a given country.

Ownership and operation of these two components varies by location. In some places (notably, most of North America) private railway companies own and operate both the infrastructure and rolling stock (for example, Union Pacific). In the United Kingdom, the infrastructure is owned and maintained by Network Rail while rolling stock is largely owned and operated by private railway companies. In countries with nationalized rail systems such as China, both the infrastructure and rolling stock are owned and operated directly or indirectly by the national government. In the European Union (EU), separation of infrastructure and operation is mandated by law, so train operation is performed by another type of company, a railway undertaking which must be provided with non-discriminatory access to any railway path within the EU. Outside the European Union it is possible that the same company is owning the infrastructure and also operating trains and in that case this designation might not make sense. Infrastructure managers charge for the use of its network.