The WebSocket protocol
The WebSocket protocol started appearing in browsers in the late 2000 and became an IETF standard in 2011. Once a handshake is negotiated over HTTP, it creates an interactive TCP connection between a server and a browser, allowing for interactive communications with very little overhead. At this point, it no longer bears any resemblance to standard HTTP.
Having a full, two-way open connection between the server and the browser allows much faster and closer to real time communications for web applications. The XMPP WebSocket API was standardized by the IETF in 2014 (for more information, see https://datatracker.ietf.org/doc/rfc7395/) and is now implemented by all of the most popular XMPP servers.
While WebSockets do have the advantages of lower latency and higher throughput, they also have a disadvantage that if the connection is severed, the connection between the server and the browser IT needs to be reconnected and the XMPP client connection must be renegotiated....
