Today, we’re excited to announce some changes to the way we release new builds to all Windows Insiders.
We are transitioning and converting our current ring model, based on the frequency of builds, to a new channel model that pivots on the quality of builds and better supports parallel coding efforts. In addition to this change, Insiders will also find similar offering names and expectations across Windows and Office programs and soon Microsoft Edge and Microsoft Teams.
Later this month, the Fast ring will become the Dev Channel, the Slow ring will become the Beta Channel, and the Release Preview ring will become the Release Preview Channel.
More Info: Windows Blog