Server-Sent Events or SSE is when the server sends events to the client in a unidirectional manner. In this video I explain Server-Sent Events and compare it to websockets and HTTP and Long Polling.   Source Code https://github.com/hnasr/javascript_playground/tree/master/server-sent-events  Resources https://developer.mozilla.org/en-US/docs/Web/API/EventSource   0:00 Intro 1:50 HTTP 1.0/1.1 3:40 WebSockets 5:00 Server Sent Events 7:30 SSE Use Cases 9:00 SSE Code Example 18:00 SSE Pros & Cons 25:20 Do You Need SSE? 28:30 Summary