The main function of a database management system (DBMS) is to facilitate the efficient storage, retrieval, and management of data in a structured format. A DBMS provides users with tools to create databases, define relationships between data elements, and execute queries to retrieve or manipulate data. It ensures data integrity, security, and accessibility, allowing multiple users to access and manage data concurrently without conflicts. DBMSs support various data models, including relational, NoSQL, and object-oriented databases, catering to diverse application needs.