Have you ever wondered how does Google shows the link to the found website itself, but when you click the link, you are first redirected to the google.com for statistics collection or whatever Google does and only then you are redirected to the website you wanted to enter ?
Server-Sent Events are a great way to solve one particular shortage of HTTP protocol, which is an asynchronous server to client communication.
HTTP itself is a request-response protocol and this is great – until you need to implement notifications, direct messages, or a similar feature. A backend server cannot send a message if the client didn’t ask for it explicitly.
Of course, there are WebSockets, but are we aware of the alternatives? Server-Sent Events is a technology, which allows us to push messages from a server to a browser in an asynchronous way. This is possible only in that direction, but isn’t it exactly what we miss in HTTP?