This book is suitable for people new to Java EE and Glassfish. The author gives a brief overview of the major parts of Java EE, but discuss nothing in detail. Basically the author tells you what is what, and give a few simple examples to help you understand it. Those examples are far far away from real world application. In summary, if you are absolute beginner in using Java EE, you may want to read it. For Glassfish, you can read its online documentation. For people with some background in Java EE, they can escape this book.