This document discusses Comet and web sockets. Comet refers to techniques for long-lived HTTP connections to allow real-time data transmission from server to browser. Common Comet methods include long-polling, forever frames, and callback polling. Web sockets provide bi-directional communication over a single TCP connection and are being standardized by the W3C, addressing limitations of Comet techniques. The document provides examples of implementing Comet using Dojo and discusses related topics like Comet servers, protocols, and clients.