This book is written for a very specific audience. If you are a junior technical person (say a programmer, systems administrator, or even an entry-level security specialist) in an organization running Office 365, Windows 10, and Azure web services, and you wish to come up to speed in the Microsoft security applications, then this is the book for you.
The book is very much a hands-on tutorial, with clear but brief explanations and lots of screen shots to help you familiarize yourself with the suite of services provided to protect the security of your users, devices, and platforms. The background on computer security is limited to what you might need to understand the applications.
As the author says, “This book is intended for starters, as each security topic is an ocean in itself and could take an entire book or more to cover.” I agree with the author’s assessment, but you must start somewhere, and this book is a good place. Not being an expert in Microsoft security, I found the numerous acronyms a bit distracting. But, if you are planning to work in this area, you will have to get familiar with them.