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The process of confirming a person's identity, which can be done through usernames and passwords or certificates.
Authentication
The process of determining what a user is allowed to access, such as specific resources, servers, or files.
Authorization
The process of verifying access control settings, providing a forensic trail after a security breach, and storing logs or records in an immutable form.
Accounting
An optional add-on to the authentication process that requires additional factors, such as a PIN, facial or retinal scan, or fingerprint, to verify a user's identity.
MFA (Multi-factor Authentication)