It doesn't really answer my question, but from what I've seen in the TOC I'd say it's equivalent to an introductory course on computer architecture + computer systems and some cryptography as well. Kind of an introduction (don't get me wrong with the word 'introduction', it covers a decent amount of material) to the most important concepts and technologies that guide computers and the internet.
Most normal people and junior devs would get a red head when reading it, techies and seniors would nod along and sometimes say "uh... so that's how it really works". It's in between but a good primer on the essentials.