Junilu, thanks so much for the great answers!
Angus, in what way do you want to understand DevOps? Are you looking to learn how it can improve your current environment? Are you looking to level up your skills? The very first paragraph of Chapter 1 "The Big Picture" in Effective DevOps has this definition for you:
Devops is a way of thinking and a way of working. It is a framework for sharing stories and developing empathy, enabling people and teams to practice their crafts in effective and lasting ways. It is part of the cultural weave that shapes how we work and why. Many people think about devops as specific tools like Chef or Docker, but tools alone are not devops. What makes tools “devops” is the manner of their use, not fundamental characteristics of the tools themselves.
Based on your answers to the previous questions, I can point you in the direction of how to gain insight. As Junilu mentions, the answer is highly subjective based on your current environment, and your current needs.