Socket.IOのnamespaceとroomの使い分けに迷ったのですが、stackoverflowにぴったりの回答がありました。 http://stackoverflow.com/questions/10930286/socket-io-rooms-or-namespacing This is what namespaces and rooms have in common (socket.io v0.9.8): Both namespaces (io.of('/nsp')) and rooms (socket.join('room')) are created on the server side Multiple namespaces and multiple rooms share the same (WebSocket) connection The server will t