This book is a fast-paced tutorial that explores the key features of EJB 3 with many accompanying examples. This book is not a complete reference guide, but a concise exploration of EJB 3s core elements. This book is primarily aimed at professional developers who already have a working knowledge of Java. Enterprise architects and designers with a background in Java would also find this book of use. Previous experience of working with Java is essential and knowledge of relational databases is desirable. As this book is an introduction to EJB 3, it is aimed at those who are new to EJB 3. As the new version of EJB is so radically different from the previous version (EJB 2.x), the book is suitable for and should be of interest to those who have had experience working with EJB 2.x. The text makes it clear where the differences between the versions of EJB lie, although they are not explored in detail.