A database system can be described as essentially nothing more than a computerized record-keeping system. A database, then, is simply a collection of structured data files and any associated indexes. The user of such a system must be able to add, insert, retrieve, update, and delete data and files as necessary. Although the SQL Standard doesn't actually define the nebulous concept "database", SQL provides all of these functions and more.

In this chapter, we'll briefly discuss SQL's fundamental concepts — how the language fits into its overall environment, the data Objects you can expect to work with, and how SQL-data and SQL statements are structured.