This document provides an overview of database management systems (DBMS) and their fundamentals. It begins with definitions of a database and DBMS, explaining that a DBMS is software that stores and manages large collections of integrated data. It then discusses why DBMS are used, the advantages they provide over file-based data storage, and common types of DBMS like Oracle, SQL Server, and Access. The document also covers basic DBMS concepts like the three-schema architecture and client-server models. It concludes with discussing different categories of DBMS and outlining factors to consider when selecting a desktop or server DBMS.