A turnstile (also called a turnpike, gateline, baffle gate, automated gate, turn gate in some regions) is a form of gate which allows one person to pass at a time. A turnstile can be configured to enforce one-way human traffic.
In addition, a turnstile can restrict passage only to people who insert a coin, ticket, pass, or other method of payment. Thus a turnstile can be used in the case of paid access (sometimes called a faregate or ticket barrier when used for this purpose), for example to access public transport, a pay toilet, or to restrict access to authorized people, for example in the lobby of an office building.
A turnstile gate with a card reader is an access control turnstile gate with card reading technology. Card readers have electronic sensors that gather information from cards to determine if a pedestrian should be allowed through an access control turnstile gate or not.