Difference between dba_* and all_* and user_* dictionary views

Difference between dba_* and all_* and user_* dictionary views

• An ALL_* view displays all the information accessible to the current user, including information from the current user's schema as well as information from objects in other schemas, if the current user has access to those objects by way of grants of privileges or roles.
• A DBA_* view displays all relevant information in the entire database. DBA_ views are intended only for administrators. They can be accessed only by users with the SELECT ANY TABLE privilege. This privilege is assigned to the DBA role when the system is initially installed.
• A USER_* view displays all the information from the schema of the current user. No special privileges are required to query these views.