What are Long-Polling, Websockets, Server-Sent Events (SSE) and Comet?

I have tried reading some articles, but I am not very clear on the concepts yet. Would someone like to take a shot at explaining to me what these technologies are: Long Polling Server-Sent Events Websockets Comet One thing that I came across every time was, the server keeps a connection open and pushes data to the client. How is the connection kept open, and how does the client get the pushed data

[mitsugi-bb]

サーバーサイドのプッシュに関してHTTP、AJAXポーリング、AJAXロングポーリング、HTML5のSSE、Websocketの解説が図になっててイメージしやすい。