Original: Depending on where it is purchased, and the length of validity, a Travelcard is either printed on a paper ticket with a magnetic stripe or encoded onto a reusable contactless electronic smart card, known as an Oyster card.
Simplified: By 1985, there were two travelcards: the Travelcard itself, which covered only London Buses and the Underground, and the Capitalcard, which covered most bus, Underground and local British Rail (BR) services.