A plastic card, the size of a credit card, that contains an embedded silicon computer chip. Its primary purpose is the portable storage and retrieval of data used to authorize various types of electronic transactions. Compared to their predecessors, magnetic stripe cards (for example, credit cards), smart cards can store data relating to more than one institution, facilitate more than one type of use, carry substantially larger volumes of data, process transactions at higher rates, and provide logical and physical security to the card's data. Smart cards work by interacting with a card reader—an interface between the smart card and an institution.