WebSockets

WebSockets is a communication protocol that enables full-duplex, persistent connections between a client (like a web browser) and a server over a single TCP connection.

Here’s a breakdown:

• Traditional HTTP is request-response based: the client sends a request, and the server responds, then the connection usually closes.
• WebSockets, on the other hand, keep the connection open, allowing both client and server to send messages to each other at any time without re-establishing connections.

Key Features of WebSockets

• Full-duplex: Both client and server can send messages independently.
• Persistent connection: After the initial handshake over HTTP(S), the connection remains open.
• Lower overhead: No need to repeatedly send HTTP headers for every message.
• Real-time communication: Ideal for chat apps, live dashboards, multiplayer games, and stock tickers.

How It Works

1. Handshake: The client makes an HTTP request asking to upgrade the connection to WebSocket.
2. Upgrade: The server accepts and upgrades the protocol.
3. Persistent channel: Both sides can now push data instantly.

Example (JavaScript)

// Client-side
const socket = new WebSocket("ws://example.com/socket");

// When connected
socket.onopen = () => {
  console.log("Connected!");
  socket.send("Hello Server!");
};

// Receiving messages
socket.onmessage = (event) => {
  console.log("Message from server:", event.data);
};

// Client-side
const socket = new WebSocket("ws://example.com/socket");

// When connected
socket.onopen = () => {
  console.log("Connected!");
  socket.send("Hello Server!");
};

// Receiving messages
socket.onmessage = (event) => {
  console.log("Message from server:", event.data);
};

Common Uses

• Chat and messaging apps
• Online multiplayer games
• Live notifications (social media, sports scores)
• Collaborative tools (Google Docs-like editing)
• Financial trading platforms (live stock/crypto prices)