It’s not about “combining” Dev and Ops, that’s just the word for it as, I think, it was coined by Patrick Debois. As stated above, it’s about providing the scaffolding or structure, and the cultural change to accept intermingling of Dev-side and Ops-side talent, to allow you bridge the DevOps gap. What they used to call “over the wall” or “over the transom” delivery of application code to IT to “take it live.”
This wasn’t a big problem when you had one gonzo big release every 12 months or so. With Agile Methodology and with cloud infrastructure, however, you can now have releases occurring every couple of weeks and into a (private or public) cloud where things can get complex fast. Flickr did a presentation earlier this year where they can do 10+ releases in a day! That rams a very large workload onto QA and Ops. DevOps refers to the movement and the recognition of the need for planning, coordination and automation tooling that has some Dev components and Ops components.