spring-security/docs/modules/ROOT/pages/servlet/authentication/unpwd/user-details.adoc

[[servlet-authentication-userdetails]]
= UserDetails

{security-api-url}org/springframework/security/core/userdetails/UserDetails.html[`UserDetails`] is returned by the <<servlet-authentication-userdetailsservice,`UserDetailsService`>>.
The <<servlet-authentication-daoauthenticationprovider,`DaoAuthenticationProvider`>> validates the `UserDetails` and then returns an <<servlet-authentication-authentication,`Authentication`>> that has a principal that is the `UserDetails` returned by the configured `UserDetailsService`.