How to update data on a page using push?

Question

Push technologies

It is required to display the current state of the system from the server on the user's screen in the browser (for example, a new message has arrived). that is, I need an event to be generated on the server, which would be sent to all browsers of users who have now opened the site.
How to do it via push? what libraries to use?

Answer 1

Is it push? Maybe it's better to use websockets?

Answer 2

Additionally, you can look at socket.io and PubSub