Socket.IO Overview Socket.IO is the most popular real-time communication library for Node.js. It provides bidirectional event-based communication between client and server, with automatic fallback from WebSocket to HTTP long-polling, reconnection handling, room-based broadcasting, and namespace isolation. This skill covers server setup, client integration, rooms, authentication middleware, scaling with Redis, and common patterns like chat, notifications, and presence. Instructions Step 1: Installation Step 2: Server Setup Step 3: Client Connection Step 4: Authentication Middleware Step 5: Sca…