The Windows team is changing the way it labels and distributes its beta and preview releases.
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.
This brings Windows beta and preview releases in line with Office, the new Microsoft Edge, and the industry at large. Even if it were just a name change, this makes a lot more sense than the weird ring names they used up until now.
Much better understanding naming convention. I welcome this.