Explanation
In Windows 10, Windows Hello for Business replaces passwords with strong two-factor authentication on PCs and mobile devices. This authentication consists of a new type of user credential that is tied to a device and uses a biometric or PIN.
After an initial two-step verification of the user during enrollment, Windows Hello is set up on the user's device and Windows asks the user to set a gesture, which can be a biometric, such as a fingerprint, or a PIN.
The user provides the gesture to verify their identity. Windows then uses Windows Hello to authenticate users.
Reference:
https://docs.microsoft.com/en-us/azure/active-directory/authentication/concept-authentication-methods
https://docs.microsoft.com/en-us/windows/security/identity-protection/hello-for-business/hello-overview