Definicja class hierarchy

The classes used to define a multi-level search path.

The initial class has subordinate classes assigned to it, and you can restrict the search systematically by choosing the appropriate subordinate class.

Example

Class VEHICLES has the subordinate classes CARS and TRUCKS. Class CARS has the subordinate classes SPORTSCARS, STATION_WAGONS, and SEDANS. When you are looking for a particular car, you can restrict the search down the hierarchy levels as appropriate.