Discord is a voice over IP program with text messages forum and private message function.
It took the voice chat from Teamspeak and added other functions.
Now gas video chat or screen sharing functions.
And if you hurt the feelings of a furry the discord owners ban you.
It sounds very dangerous for a child. I never had much experience with gaming with my kids. Their gaming was all with things like X-box or play station. They had them, but they were too busy to waste much time on them. Creating private chat rooms sounds way too dangerous and difficult to control.