Fingerprint scanners are devices that capture and analyze the unique patterns of ridges and valleys on a person's fingertips. They are commonly used for security purposes, allowing access to smartphones, computers, and secure facilities. By scanning a fingerprint, the device can quickly verify a person's identity. These scanners work by using sensors to create a digital image of the fingerprint. The image is then processed to extract specific features, which are compared to stored fingerprints in a database. If there is a match, access is granted; if not, the attempt is denied. This technology is part of the broader field of biometrics.