This document discusses WebSockets and their advantages over traditional AJAX polling for real-time applications like games and stock tickers. WebSockets allow for full-duplex communication over a single TCP connection, making them more efficient than polling approaches. They have become a standard in HTML5 and support on browsers is improving, though fallbacks like SockJS are still needed. Popular server-side implementations include Node.js and the Java WebSocket API integrated with frameworks like Spring. WebSockets also integrate well with messaging architectures using brokers like RabbitMQ. Security considerations include using WSS instead of WS and validating input/output.