WebSocket

Summary

A persistent, full-duplex connection between browser and server that enables real-time, bidirectional communication — used for chat, live notifications and live dashboards. Unlike ordinary request-response communication, a WebSocket stays open so either side can send messages whenever needed, making it well suited to live application state.

• 1Connect to a public WebSocket echo server and send/receive a message. Validate your understanding by applying it in a small practical example.
• 2Learn the WebSocket lifecycle events: `open`, `message`, `close`, `error`. Focus on understanding the underlying reason it works, not only memorizing the definition.
• 3Compare WebSockets to polling — understand why they're more efficient for real-time features.