Fingerprint scanners are devices that capture and analyze the unique patterns of ridges and valleys on a person's fingertip. They are commonly used for security purposes, allowing access to smartphones, computers, and secure facilities. The technology works by converting the fingerprint into a digital format, which can then be compared to stored fingerprints for verification. These scanners come in various forms, including optical, capacitive, and ultrasonic types. Each type uses different methods to capture the fingerprint image. Fingerprint scanners are popular due to their convenience and the high level of security they provide compared to traditional passwords.