A card reader is a device that allows users to read data from various types of cards, such as credit cards, debit cards, and identification cards. It typically connects to a computer or mobile device, enabling the transfer of information stored on the card's magnetic stripe or chip. Card readers are commonly used in retail, banking, and access control systems. These devices come in various forms, including handheld models and built-in readers in point-of-sale systems. Many card readers also support contactless payments, allowing users to tap their cards for quick transactions. They play a crucial role in enhancing security and convenience in financial transactions.