What's the difference between Developer Edition and Vanilla Firefox or Nightly? The home page just describes features which seem to be in plain Firefox. Last t

What's the difference between Developer Edition and Vanilla Firefox or Nightly? The home page just describes features which seem to be in plain Firefox. Last time I searched for details, I could only find unofficial answers in Stack Overflow and such, much of them probably obsolete. I want to know what I install, not blindly trust some ridiculous PR: "Firefox Quantum: Developer Edition. Welcome to your new favorite browser. Get the latest features, fast performance, and the development tools you need to build for the open web."