Web Socket, WS/WSS

WS, WSS, Websocket → Interaction or two-way communication based on HTML5 and HTTP(S)

WebSocket (웹소켓)

WebSocket is based on HTTP(S) and was introduced in HTML5

It is a technology that realized real-time interaction (two-way communication) which was difficult between HTTP server and client,

WebSocket connects to the server using port 80 and port 443 for HTTP (ws://) and HTTPS (wss://), respectively.

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1. Socket.IO

Socket.IO provides the most general-purpose module or library,

It required implementing event-based, real-time, and bidirectional Websocket communication in the server and client.

♦ Server Socket.IO

io.on(‘connection’, callback(socket))	The socket is connected and a new client connects.
socket.on(event-name, callback(data))	Receive event, Process message/event through callback function for the event from the client socket.
socket.emit(event-name, data)	Sending an event Sending data to a specific client with some event.
socket.broadcast.emit(event-name, data)	Send event Send data to all clients with some event.
io.of(name-space)	Set up sending and receiving messages in the same namespace

♦ Client Socket.IO

io.connect( )	Create a socket.
socket.on(event-name, callback(data))	Receive event Process message/event through callback function for certain event. .
socket.emit(event-name, data)	Send event, Send data to server with some event.
io(name-space)	Set up sending and receiving messages in the same namespace