Mapping in DBMS refers to the process of connecting data fields from one database to another. It is a crucial step in data migration, data integration, and other data management tasks. Mapping ensures that data is accurate and usable at the destination, and it bridges the differences between two systems or data models. There are different types of mapping in DBMS, including external/conceptual mapping and conceptual/internal mapping.

Mapping constraints in DBMS are used to establish connections between entities, particularly when there are scenarios involving multiple relationships for a given entity. Mapping constraints play a significant role in database design and management, contributing to data integrity, query optimization, database consistency, and more. They assist in generating meaningful queries and reports from the database, dictate how data can be manipulated and updated in the database, and enhance the understanding of the database structure and relationships.

In summary, mapping in DBMS is a process of connecting data fields from one database to another, and it is crucial for data migration, data integration, and other data management tasks. Mapping constraints in DBMS are used to establish connections between entities and play a significant role in database design and management.