Views related to permissions and roles in Oracle

The views related to permissions and roles include the following:
Dba_sys_privs: query the system permissions of a user
User_sys_privs: system permissions of the current user
Session_privs: All permissions of the current user
Role_sys_privs: system permissions of a role

Note: You need to log on to the view as a sys user to query this view. Otherwise, null is returned.

Role_role_privs: role assigned to the current role
Session_roles: Role activated by the current user
User_role_privs: role assigned to the current user