https://www.tomshardware.com/news/microsoft-accounts-passwordless-login-fido2,38100.html
 
Via a hardware token, users with a FIDO 2-enabled drive are able to skip manual introduction of any authentication in both Windows (version 1809 and up) or any supporting website (with a browser that supports the FIDO 2/WebAuthn API. It basically creates a security key using cryptography, where the user only has to press a button on the security key to log into a website. Microsoft has partnered with Yubico for a while now on developing this security mechanism, and the company's FIDO 2 keys are now compatible with the OS. Sounds like a very secure method unless the FIDO 2 device becomes infected with malware.