In ServiceNow,tablesfollow an inheritance model, where tables can be extended from other tables. The distinction betweenBase Class tablesandParent Class tablesis as follows:
Base Class Table:
ABase Class table is not extended from any other table.
It exists at the top level in the table hierarchy.
Example:Task [task],Configuration Item [cmdb_ci]are base tables.
Parent Class Table:
AParent Class table may be extended from another tablebut also has tables extending from it.
It acts as a bridge between the base table and other extended tables.
Example:Change Request [change_request]extends fromTask [task], makingTaskthe base class andChange Requesta parent class to other change-related tables.
A. Base Class tables always have tables extended from them, Parent tables do not have tables extended from them.
Incorrect because not all base tables have extensions.
Parent tablesdohave extended tables.
C. Extended tables can be extended from Parent tables or Base tables, but they cannot be extended from both.
Incorrect because extended tables caninheritfrom other extended tables in a multi-level hierarchy.
D. Extended tables are always extended from Parent tables, Extended tables are usually extended from Base tables.
Incorrect becauseextended tables can come from either Base or Parent tables, not just Parent tables.
Table Inheritance in ServiceNow
Extending Tables
Definitions:Why Other Options Are Incorrect?Official ServiceNow Documentation Reference: