The process of generalizing entities, where the generalized entities contain the properties of all the generalized entities, is called generalization. In generalization, a number of entities are brought together into one generalized entity based on their similar characteristics. Specialization is the opposite of generalization. In specialization, a group of entities is divided into sub-groups based on their characteristics.

Here, Motor-Vehicle is the generalized entity, which has some specialized entity like Motor-Cycle, Vans, Buses, and Passenger Cars. These specialized Entities have their own specialized Model. But all entities have the common attributes i.e. Registration number as their generalized entity, Motor-Vehicle. The Relationship has been presented here via ISA Relationship.