This document defines and describes different types of databases and database management systems (DBMS). It discusses centralized and distributed databases. A DBMS provides access to organized data, minimizes redundancy and inconsistencies, and allows data sharing. Key functions of a DBMS include data filtering, quality control, synchronization, and maintenance. DBMS offer advantages like permanence, querying, concurrency controls, backups, security, and computation. A DBMS also provides both a physical and logical view of stored data.