This book focuses on the visual communication and documentation of software architecture. I've seen a number of debates over the years about whether software development is a craft or an engineering discipline. Although I think it should be an engineering discipline, I believe we're a number of years away from this being a reality. So while this book doesn't present a formalised, standardised method to communicate software architecture, it does provide a collection of ideas and techniques that thousands of people across the world have found useful. The core of this is my C4 software architecture model and the software guidebook. You'll also find discussion about notation, the various uses for diagrams, the value of creating a model and tooling.
This book was formerly called "The Art of Visualising Software Architecture", and now additionally includes information about documentation.