socket.io key features usedrooms and namespace API With the groups API you can perform various action in a group,Important features can be summed up as:join/leave group AND send messages to server or group
// join and leave
io.on('connection', function(socket){
socket.join('some group');
// socket.leave('some group');
});
// say to group
io.to('some group').emit('some event'):
io.in('some group').emit('some event'):