Database System Architecture - Access Database Design and Programming - page 112

Figure 7-2. The relationships and structure of the Jet Database Engine (DBMS)
Microsoft's application-level products Visual Basic, Access, and Excel play host to VBA,
which is the underlying programming language (also called scripting or macro language)
for these applications. (Microsoft Word Version 7 does not use VBA—it uses a similar
language called Word Basic . However, as of Microsoft Word 97, Word does use VBA.)
As expected, each of these applications integrates VBA into its environment in a specific
way, since each application has a different purpose.
In turn, Visual Basic for Applications is the host language for the Jet DBMS. The Jet
DBMS contains the DAO component, which is the programming-language interface for
the Jet DBMS. The DAO provides a more-or-less object-oriented DDL and DML,
thereby allowing the VBA programmer to define the structure of a database and
manipulate its data.
The Jet Database Engine is a collection of components, generally in the form of dynamic
link libraries ( DLLs), designed to provide specific functions within the Jet DBMS. (A
DLL is essentially a collection of functions for performing various tasks.) The Jet Query
Engine handles the translation of database queries into Access SQL, and the subsequent
compilation, optimization, and execution of these queries. In short, it handles queries.
The Internal ISAM component is responsible for storing and retrieving data from the