Unwatching a group

1: whaat does “watch group” actually do?
2: I just unjoined a group and it worked. Now when I go to the group rwo boxes come up. One is Join Group - so far so good.
But the other is green and says Watch Group. I can’t toggle it.
Using iPad Pro. Latest iOS update.
TIA

If I click on Watch Group, it changes to Watching, but is still green and the same size. Clicking again changes it back.

There are some groups you can watch, but not join, like Book Talk.

If you watch a group, it shows up in talk if you go to Your Groups. But it is a little less public than joining.

Thanks. Just an FYI - I am legally blind and can barely differentiate between black and green backgrounds and that was why I wasn’t seeing the wATCHING toggle. All good now.

My sight is rapidly going downhill. I didn't see the change well either. It isn't very obvious.