TCP vs UDP

• TCP: Transmission Control Protocol
• UDP: Universal Computer Protocol. When some packets can be loss.

Socket

: connection which clients should pass when request, response data.

• TCP socket, UDP socket
• Web socket: ex) google docs

socket.io: Not all browsers can use web socket. socket.io library can help live polling.

Introduction

using socket.io

shopping mall real-time buy alert

HW

실시간 카운터 기능 구현