Hey there @benno.krauss welcome to the community!
Great question! At a high level they are 2 distinct approaches to authentication:
- Passkeys are a form of passwordless login using cryptographic keys.
- Identifier first + Biometrics relies on a user entering a username, email, etc. and subsequently physical traits for identity verification.
While passkeys can be used independently of biometrics, combining them enhances security, ensuring that the cryptographic keys are only accessible to the biometrically authenticated user.
This is just the tip of the iceberg so to speak, but I hope this helps to at least clarify the difference between the two!