Specialization is a concept in database management systems (DBMS) that involves breaking down a higher-level entity into smaller, more specialized entities. It is a top-down approach that is used to find subsets of an entity that have different or additional attributes. Specialization is usually used to establish superclass-subclass relationships. In this approach, the lower-level entities share the attributes of the higher-level entity, but also have specific attributes of their own.

For example, in an employee management system, the "employee" entity can be specialized into "tester" or "developer" based on the role they play in the company. The "employee" entity has attributes such as name, phone number, and address, while the "tester" entity has additional attributes such as test type.

Some key points about specialization in DBMS include:

• It is a top-down approach
• It is used to find subsets of an entity that have different or additional attributes
• Lower-level entities share the attributes of the higher-level entity, but also have specific attributes of their own
• It is usually used to establish superclass-subclass relationships

Overall, specialization is a useful concept in DBMS that allows for more efficient and organized data management.