A database management system is simply the software that permits an organization to centralized data, manage them efficiently, and provide access to the stored data by application programs. The database management system acts as an interface between application programs and the physical data files.

When the application program calls for a data item such as gross pay, the database management system finds this item in the database and presents it to the application program. Using traditional data files the programmer would have to define the data and then tell the computer where they were. A database management system eliminated mist of the data definition statements found in traditional programs.

A database management system has three components such as DDL, DML and DCL. The Data definition language is the formal language used by programmers to specify the content and structure of the database. The data definition language defines each data elements ass it appears in the database before that data element is translated into the forms required by application programs.