Factors - different pieces of evidence which prove identity.
Common factors used:
- Knowledge - something you know: usernames, passwords.
- Possession - something you have: bank card, MFA device/app.
- Inherent - something you are: fingerprint, face, voice, iris.
- Location - a location (physical) or network (corporate or home wifi).
More factors == more security and harder to fake identity. But more factors == less convenience. We want to achieve a balance between security and convenience.
