The Oracle Data Dictionary contains information about data base objects, users and events. You can access this information through these views of the data dictionary.

ViewDescription
USER_ROLE_PRIVSRoles granted to the user.
USER_TABLES aka TABSDescription of the user's own tables.
USER_TAB_COLUMNS aka COLSColumns of user's tables, views and clusters.
USER_TAB_PRIVSGrants on objects for which the user is the owner, grantor or grantee
USER_VIEWS Test of views owned by the user.
USER_TRIGGERSDescriptions of the user's triggers
USER_OBJECTS aka OBJObjects owned by the user
USER_INDEXES aka INDDescription of the user's own indexes
USER_IND_COLUMNSColumns of the user's indexes or on user's tables
USER_SEQUENCES aka SEQDescription of the user's own sequences