The MetroCard is a smart card used for fare payment on the New York City Subway and MTA buses. It was introduced in 1993 to replace tokens and paper tickets, making it easier for riders to pay for their trips. The card can be loaded with a specific amount of money or unlimited rides for a set period. Riders can purchase a MetroCard at vending machines or ticket booths located in subway stations. The card can be refilled as needed, and it offers discounts for bulk purchases. It is a convenient way to navigate the extensive public transportation system in New York City.