This video is the third part of an introduction to the concepts and vocabulary of Database. We discuss a database in the context of the client-server model/paradigm. Then we talk about prescriptive versus descriptive approaches to problem (and generations of computer languages). We move on to SQL (Structured Query Language) and its constituent parts: the Data Definition Language (DDL), the Data Manipulation Language (DML), and the Data Control Language (DCL). Finally we consider some of the roles a person interacting with a Database Management System (DBMS) might play -- such as user of Database Administrator (DBA).