A DBMS is system software that manages data storage, access, modification, and integrity in a structured database. It allows users to create, read, update and delete data systematically and serves as an interface between users and the database. Common applications of DBMS include banking, airlines, universities, telecommunications, finance, sales, manufacturing, and human resources. The most widely used type of DBMS is the relational DBMS which stores data in tables that can be related through joins. Other types include hierarchical, network, and object-oriented DBMS.