A EuRail or InterRail pass will generally grant a passenger free transportation on an ordinary train (for example, EuroCity trains and Regional) and passage with reservations on premier trains (such as TGV, Thalys, Eurostar, Eurostar Italia, AVE and all night trains).
The EuRail Group G.I.E. (sometimes referred to as Eurorail) is a Netherlands-based company, registered in Luxembourg, that sells passes and tickets for European railroads. It is owned by a group of European rail carriers and shipping companies.
Its principal products are EuRail passes and InterRail passes, with which a passenger has largely unlimited ability to travel on nearly all European railroads and some shipping lines at a fixed price per day of travel or travel within a certain number of days.
EuRail passes are available only to Non-EU Residents whereas InterRail passes are only available to EU Residents.