A  one-to-many algorithm identifies and authenticates a person using the  fingerprint as the only piece of information. As the fingerprint is  submitted for authentication, it is compared against all the  fingerprints from all the persons enrolled until it finds a match.

A  one-to-one algorithm uses a specific unique identifier (like a  username) to determine which person is about to attempt authentication.  As the fingerprint is submitted, it is compared against only the  fingerprints from the person determined by the unique identifier.