Donovan Brown himself described What is DevOps? as the following;
DevOps is the union of people, process, and products to enable continuous delivery of value to our end users.
I am very deliberate in the terms used in this definition. I choose value over software. DevOps is not just automating a pipeline so we can quickly deliver software. Our goal is to deliver value. The term end users was also very carefully chosen. The value we produce must reach our end users. If the value only reaches the Dev and QA environments but is held up before reaching production where it can be realized by our end users, we are still failing.
It is very important to realize that DevOps is not a product. You cannot buy DevOps and install it. DevOps is not just automation or infrastructure as code. DevOps is people following a process enabled by products to deliver value to our end users.
You can find the official DevOps page of Microsoft in What is DevOps? page.