microsoftedgeinsider[.]com/en-us/
The backstory...
Today their are 5 major web browser engines -- the programming that converts the code on a web page to what you see on-screen.
wikipedia[.]org/wiki/Browser_engine
Google's open source Chromium engine is arguably the most popular, & it's also used by several brands besides Google, e.g. Opera. Microsoft has Internet Explorer, and it's still there in Windows 10, primarily for businesses that need its compatibility with in-house sites and apps. But Internet Explorer's old, so they totally reinvented it as Edge, as a part of Windows 10. Problem 1) it's part of Windows 10, so it's updated with Windows 10, Not when an update is needed, e.g. when a new vulnerability is discovered. Problem 2) problem one probably doesn't matter much, because no one wants to use Edge. So Microsoft is scrapping most of the work it did creating Edge, building a completely new version based on Google's Chromium engine -- a Microsoft version of the Chrome browser if you will. And they're almost done.
Microsoft is decoupling Edge from Windows, and they want to push it out for most versions of Windows, Linux, Android, iOS etc. They also trying to adapt & include most of the features in Edge that the few people using it liked. While today the release candidate for the new Edge is out in Beta, early next year Microsoft is expected to push it out to all Windows 10 users. Now it installs alongside the old Edge -- then I believe it'll like replace it. But the plot may thicken...
Microsoft is basically done with the version of Windows 10 that would in the past be pushed out next spring, around March or April. Its RTM -- when it's officially done -- is supposed to happen in December, in line with the scheduling of several other Microsoft products. Microsoft may sit on it for 3 months or so, or it may change the schedule, so Windows 10 version updates happen in January rather than March. A new Windows 10 version in January could come with the new Edge in place of the old, eliminating any need to upgrade the old version. However it happens though, the writing's on the wall -- the old Edge everyone hated is no more.