The author talks a lot and says very little. Significant portions of the book are spent not explaining or conveying any useful knowledge (especially not the kind that may enable the reader to understand the underlying concepts regardless of specific products), but instead throwing around big words and showcasing products the author recommends. I read this book starting out and was none the wiser, later read it again after several years of self-study, and I reckon I could give a more comprehensive introduction given two hours and a computer for demonstration purposes.