What is two-factor authentication?
Two-factor authentication (2 factor authentication or 2FA) is the authentication process where two of the three possible factors of authentication are combined.
The possible factors of authentication are:
- something the user knows
- something the user has
- something the user is
In internet security, the most used factors of authentication are: something the user has (e.g. a bank card) and something the user knows (e.g. a PIN code). This is two-factor authentication. Multi-factor authentication is when a user uses 2 or more factors.