Interrail is a train ticket, and bought at any station and mainline train recently, some travel agencies. With the ticket you can get without paying almost all the trains you want and brings no default route. It is valid for a period of time, for some certain countries, depending on the airline you choose (in any case it is valid for your country). We can use those born in countries making up the offer, and the price varies depending on if you are under 26 years old (young pass) or over 26 (adult pass) and modality chosen ticket. Interrail can be global or local (to travel alone in a country individually). The length of the bill varies depending on whether global, flexible or local passes.