[1] It is contrasted to a point-to-point ticket in that it allows the holder unlimited travel, within the pre-designated area and period, while a point-to-point ticket only permits the holder to travel from a point to another once.
It is different from a season ticket in the sense that, while both of them grant unlimited travel to the holder, season tickets normally target commuting travellers, whereas rail passes usually target tourists.
Owing to its success, many other passes have been issued by various railway companies all around the world since then.
Usually the holder would need to fill in the date he travels on the pass before boarding on the train.
[5] Some countries offer concession pass to youth (e.g. age below 26) or elderly.
In some countries, rail pass holders can travel on sleeper or couchette compartment freely, while some may need to pay some extra fee or are totally restricted from taking sleeper or couchette trains.
In order to enjoy the discount, some flexipasses require the holder to spend a travel day - fill-in that date on the pass - while others do not; some of the passes also cover the cost of travelling by certain buses, ferries or cable cars.