This directory contains components that implement OS User authentication (local authentication, opposed to online GAIA/SAML authentication), and management of local authentication factors.
With Cryptohome modernization it is now possible to decouple authentication phase from the rest of the login logic, and turn it into component reused on Login / Lock screens, as well as for other in-session authentication, e.g WebAuthN flow.
Eventually authentication-specific logic would be moved from //chromeos/ash/components/login to this component.
See also //chrome/browser/ash/login/osauth for elements that depend on browser stack (such as policies).