A keycard is a small, plastic card that allows you to access secure areas, like hotel rooms or office buildings. Instead of using a traditional key, you simply swipe or tap the keycard on a reader to unlock a door. This technology is convenient and helps keep places safe by limiting access to authorized individuals. Keycards often use magnetic strips or RFID (Radio Frequency Identification) technology to work. Many hotels, for example, provide guests with keycards that are programmed for their specific room. This system not only enhances security but also makes it easier for people to enter and exit without carrying bulky keys.