In contrast to the other reviewers, I found this the most dull and badly written computer book I have ever read. It can never have been proof-read. It is full of careless errors - there are even some in the answers to the questions. The book leaves gaps in your understanding all over the place, and doesn't flow. The aim seems to be learning by committing disjointed facts to memory, rather than imparting understanding. This is not a dull subject if it is taught by enthusiasts, but the authors of this book do not seem to have the spark of life within them. I give it one star for the included CDs, and for giving an idea of what's expected in the exam.