micropython radio channel and MakeCode radio Group

I'm confused about how radio Group in MakeCode relates to radio channel in micropython. After numerous attempts I've failed to get any communication between one microbit programmed in micropython and another programmed in MakeCode. I see that micropython also has a setting for Group which adds to my confusion.

I'd appreciate if someone could clarify this.

(Can't see how to add labels to this post. Does someone else do this?)

No files, tests, or entry points are identified in the issue. First clarify how MakeCode radio Group, MicroPython radio channel, and MicroPython Group relate, then document the explanation and confirm that it addresses communication between MicroPython and MakeCode programs.

Written by the indexing model from the issue text.