A keycard reader is an electronic device used to gain access to secure areas by reading a specially encoded card, known as a keycard. These readers are commonly found in hotels, offices, and other facilities where controlled access is necessary. When a keycard is swiped or tapped against the reader, it verifies the card's information and grants or denies entry based on the access permissions associated with that card. Keycard readers can operate using various technologies, including magnetic stripes, RFID (Radio Frequency Identification), and smart cards. They enhance security by allowing only authorized individuals to enter restricted areas, reducing the risk of unauthorized access. Many systems also allow for easy reprogramming of keycards, making it simple to update access rights as needed.