A database is an organized collection of data. A database may be on paper, or held in computer files such as spreadsheets or more formally in a software system known as a computerized database management system (for example: DB2, db4o, IMS, MS Access, MS SQL Server, mySQL, Oracle, Sybase, Total, Versant). In this book we focus on Relational databases and one specific relational database system: Microsoft Access.
There are many different commercial relational database systems and what you learn here will assist you in using those others. Because MS Access is a workstation/personal system it is a convenient system for beginners.