What Is a Relational Database?

Databases store data that occurs in a particular context. For instance, a sales database contains information about your customers, products, orders, suppliers, and sales representatives. If you stored that information in a spreadsheet program like Excel or a flat-file database program, the program would make no connection between a customer (stored in one place) and that customer's orders (stored in another place).

Access, however, is a relational database, which means that you can define relationships among the data it contains. If you construct a relational database with tables listing customers and customer orders, you can define a connection between those tables based on a common field (in this case, probably a customer's identification number) (Figure 1.3).