Smart cards are small, portable devices that contain embedded microchips, allowing them to store and process data securely. They are commonly used for various applications, such as payment systems, identification, and access control. Smart cards can be contact-based, requiring a physical connection to a reader, or contactless, using radio frequency technology for communication. These cards enhance security by encrypting sensitive information, making them difficult to counterfeit. They are widely used in industries like banking, healthcare, and transportation. Examples of smart cards include credit cards, ID cards, and transit passes, which streamline transactions and improve user convenience.