Server push describes a style of Internet-based communication where the request for a given transaction is initiated by the publisher or central server.
Push services are often based on information preferences expressed in advance. This is called a publish/subscribe model.
A client might "subscribe" to various information "channels". Whenever new content is available on one of those channels, the server would push that information out to the user.
E.g. APPLE Push notifications or Android Push notifications.
