The document discusses database management systems (DBMS) and relational database management systems (RDBMS). It defines a DBMS as software used to create and manage databases. Key points made include that a DBMS provides systematic ways to create, retrieve, update and manage data stored in databases. It also discusses the different types of relationships that can exist between tables in a relational database, including one-to-one, one-to-many, and many-to-many.