The default security realm myrealm contains all the required WebLogic security providers and the embedded LDAP server in which the security providers store their security data. In order to start using the default security realm, all you have to do is to define your users, groups, and security roles for the security realm and create security policies to control access to the WebLogic Server resources. In most environments, all you ever use is the default security realm.
You need to change the default security configuration by performing the following types of operations when you want to add new custom security providers or modify existing providers:
Replace or configure new security providers.