What are the three main categories of authentication factors?

beginner

Re-explain

The three main categories of authentication factors are:

Something You Know (Knowledge Factor)
- Passwords, PINs, security questions
- Passphrases, patterns
Something You Have (Possession Factor)
- Mobile phones, hardware tokens, smart cards
- SMS codes, authenticator apps
Something You Are (Inherence Factor)
- Biometric identifiers like fingerprints, facial recognition
- Voice recognition, iris scans, retinal patterns

True MFA requires at least two different categories, not just two factors from the same category (like password + security question).

Rewriting in plainer words…

This answer doesn't lend itself to a diagram - it reads best . No credits were charged.

Why there's no diagram: “”

The interactive diagram is below the answer - jump to diagram ↓ · Below it, the related concept . Jump to it ↓

The diagram below the answer is the concept . Jump to it ↓

Tailored explanation · switch back to · ·

What should the new diagram focus on?

How well did you know this?

AI:

Saved in this browser - sign in to keep your review list.

How should your speech become text?

Listening… your words appear above as you speak - tap Stop when you're done.

Recording · cr - tap Stop & transcribe when you're done.

Transcribing with AI…

Voice:

Keep going - a few more words and AI can grade it.

Interview lens

Likely follow-ups, what you can say, and the weak answers to avoid.

Want a quick review of the fundamentals? See the Authentication & Authorization cheatsheet.

Pro · $10/mo

Full answers, code samples, and AI explanations that go simpler or deeper. Cancel anytime.