A Database is a collection of persistent data that is used by the application systems of some given enterprise.
Database system is a computerized system whose overall purpose is to store information and to allow users to retrieve and update that information on demand.
The Database management system (DBMS) provides users with a perception of the database that is elevated somewhat above the hardware level, and it supports user operations that are expressed in terms of that higher-level perception.
Structured Query Language (SQL) is a database computer language designed for managing data in RDBMS, and originally based upon relational algebra.
Closure is a set that is closed under an operation or collection of operations.

Intro to MS Access

Microsoft Office Access (known as Microsoft Access) is a relational database management system (RDBMS) by Microsoft Co. This RDBMS combines the relational Microsoft Jet Database Engine with graphical user interface (GUI) and software development tools. MS Access is a member of the Microsoft Office suite of applications.
Review hierarchy of MS Access facilities оn the fig.1.

All database tables, queries, forms, reports, macros, and modules are stored in the Access Jet database as a single file. For query development, Access offers a Query Designer, a GUI that allows users to create queries without knowledge of the SQL programming language. In the Query Designer, users can "show" the data sources of the query (which can be tables or queries) and select the fields they want to be returned by clicking and dragging them into the grid. Joins can be created by clicking and dragging fields in tables to fields in other tables. But to manipulate the SQL code can be more convenient than to use Query Designer for complicated queries and Access allows users to view, and manipulate the SQL code if desired.
Access allows user to use some functions and expression in queries (for example, iif() and nz()).
Macro is a ordered set of instructions that is represented in an abbreviated format. Macro can use commands and objects database for representation. The programming language available in Access is, as in other products of the Microsoft Office suite, Microsoft Visual Basic for Applications (VBA). VBA code can be stored in modules and code behind forms and reports. To manipulate data in tables and queries in VBA, two database access libraries of Component Object Module (COM) components are provided:
• the Data Access Objects (DAO), which is included in Access;
• ActiveX Data Objects (ADO).
Beside DAO and ADO, developers can also use OLE DB and ODBC for developing native C/C++ programs for Access.
Level API presents a set of functions of current Operation System (OS).