Divided topologically, this book starts at the remedial level and moves up to refresher for experts. Occasionally, the speed at which it goes from basic to advanced is a bit rushed (not a good book for the IT idiot who thinks their computer is broken because they kicked out the power cable - e.g. half my coworkers). The topics are all fairly interesting, but occasionally the book goes off on MBA tangents - many of the chapters were designed first and foremost for business managers/operators trying to understand IT better, as opposed to a general IT community. ( )