What is the science of recognizing humans based on physical characteristics?

Biometrics is the science that focuses on identifying individuals based on their physical characteristics, such as fingerprints, facial recognition, voice patterns, or iris scans. This technology is increasingly utilized in security systems to grant access to authorized users, as it provides a method of authentication that is unique to each individual.

Biometric systems work by capturing a sample of the characteristic to be measured and comparing it against data stored in a database. Because physical traits are generally unique to each person and difficult to replicate, biometrics offers a high level of security compared to traditional password systems.

The other options do not pertain to the science of human recognition based on physical traits. For instance, mantraps are physical security measures that involve a controlled entryway designed to limit access, while tailgating refers to unauthorized entry by following an authorized user. CAC, or Common Access Card, is a type of identification card used by the U.S. Department of Defense, but it does not involve the direct recognition of physical characteristics in the same way biometrics does.