# Storage Mechanisms

Each of the supported mechanisms for reading a username and password can leverage any of the supported storage mechanisms:

* Simple Storage with [In-Memory Authentication](in-memory.html#servlet-authentication-inmemory)

* Relational Databases with [JDBC Authentication](jdbc.html#servlet-authentication-jdbc)

* Custom data stores with [UserDetailsService](user-details-service.html#servlet-authentication-userdetailsservice)

* LDAP storage with [LDAP Authentication](ldap.html#servlet-authentication-ldap)

## Section Summary

* [In Memory](in-memory.html)
* [JDBC](jdbc.html)
* [UserDetails](user-details.html)
* [UserDetailsService](user-details-service.html)
* [PasswordEncoder](password-encoder.html)
* [DaoAuthenticationProvider](dao-authentication-provider.html)
* [LDAP](ldap.html)

[Digest](digest.html)[In Memory](in-memory.html)

