The events that flow from the webserver to the browsers are called server-sent events. DOM events can be continuously pushed from the webserver to the browser of a user. To use a server-sent event (SSE), you should add an <eventsource> element to the document. The src attribute of this element describes the HTTP connection location, which sends a data stream having the events.
Example : <eventsource src = "/cgi-bin/myfile.cgi" />
