Authentication is the process of verifying the identity or other attributes of an entity (user, process, or device). Entering in log in credentials to gain access to a website is an example of authentication, whereas using a fingerprint to gain access to a building or cell phone is another example of authentication; otherwise known as biometric authentication.
Related Term: Authenticate, Biometric Authentication
Training Video: Two-Factor Authentication, Authenticity, Identity and Access Management, Password
Source: CNSSI 4009, NIST SP 800-21, NISTIR 7298