This is a way to play Minecraft that feels like LAN but it actually works over the internet.
From what I see you just host your world like a normal LAN world or a local server. Then your friends join the same room in the program and the game shows your world like it is on their LAN too.
It is nice because you do not need port forwarding or a public IP. It also works even if you are stuck behind weird internet stuff like CGNAT or a dorm network. You just install it click a few things and start playing together.
If your router and ports are already set up then you probably do not need this. But if you keep fighting your network and nothing works this looks like an easy way to play Minecraft with your friends without all the networking pain.
