This document provides an overview of different database management systems:
- It defines a database and DBMS, and describes their basic functions.
- It explains the features of a relational database including tables, rows, columns, primary keys and relationships.
- It describes object-oriented databases, including object identity, classes, inheritance and encapsulation.
- It discusses object-relational databases as putting an object-oriented front end on a relational database.
- It briefly covers advantages and disadvantages of relational, object-oriented and object-relational databases.