Biometric scanners are devices that identify individuals based on unique physical or behavioral traits. Common traits used include fingerprints, facial recognition, iris patterns, and voice recognition. These scanners convert the traits into digital data, which is then compared to stored information to verify identity. These systems are widely used for security purposes, such as in smartphones, security systems, and access control for buildings. They offer a convenient and often more secure alternative to traditional passwords or keys, as biometric traits are difficult to replicate or steal.