I've been using VSTS (Visual Studio Team Services) for a few years now, and I think it's great. But this looks like they've just changed the URL and stuck the name "Azure DevOps" onto the VSTS site? Even the pricing and plans seem to be the same - I really don't get how they're talking like they're launching something new, rather than just having a rebranding exercise after buying GitHub.
That's exactly what it is: https://visualstudio.microsoft.com/team-services/ Although there have been slight tweaks and UI/UX updates.
In particular, I'm not a fan of the most recent changes to the 'build and release' pages. To edit the build pipeline, the edit link is at the top of the list of builds, rather than at the top of the list of build pipelines... I end up searching for the link every. single. time :(