What is Electronic Ticket?

Legal Definition
An electronic ticket (commonly abbreviated as e-ticket) is a digital ticket. The term is most commonly associated with airline issued tickets. Electronic ticketing for urban or rail public transport is usually referred to as travel card or transit pass. It is also used in ticketing in the entertainment industry.

An electronic ticket system is a more efficient method of ticket entry, processing and marketing for companies in the railways, flight and other transport and entertainment industries.
-- Wikipedia
Legal Definition
Electronic airline, train, or any type of travel-ticket. Using personal id and ticket code, the traveler retrieves the ticket at a machine or travel service agent. Refer also to paperless ticket.