Radio-frequency identification (RFID) is a technology that uses radio waves to identify and track objects. It consists of two main components: a tag and a reader. The tag contains a microchip and an antenna, which store and transmit data when activated by the reader's radio signal. This allows for automatic identification without the need for direct contact. RFID is commonly used in various applications, such as inventory management, access control, and supply chain tracking. It offers advantages like increased efficiency and accuracy compared to traditional barcodes, as it can read multiple tags simultaneously and does not require line-of-sight scanning.