Relational database technology enables people to represent information as data stored in computers and to use that data to assist with the running of their businesses. It is now relatively cheap, and can be used on even simple personal computers. This book aims to provide an understanding of: the ideas which lie behind relational database technology; programs and techniques which are used to apply the technology; and the next generation of database technology which will either replace or complement relational technology. It is assumed that the reader has some basic computer literacy but has no prior knowledge of database technology. The book is aimed mainly at undergraduate students seeking, for example, BTEC or BSc qualifications, but it may also help people who want to buy and use a database system to appraise and make effective use of "relation database" products.