Network Rail is the government-created owner and operator of most of the rail infrastructure in Great Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

 (England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

 and Wales

Wales

Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

).; it is not responsible for railway infrastructure in Northern Ireland

Northern Ireland

Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...

. Network Rail is a British "not for dividend" entity, technically a private company limited by guarantee, whose principal asset is Network Rail Infrastructure Limited, a company limited by shares

Private company limited by shares

A private company limited by shares, usually called a private limited company , is a type of company incorporated under the laws of England and Wales, Scotland, that of certain Commonwealth countries and the Republic of Ireland...

.

Network Rail's main customers are the separate and mostly private-sector train operating companies (TOCs), responsible for passenger transport, and freight operating companies (FOCs), who provide train services on the infrastructure that the company owns and maintains.