Publish–subscribe pattern

In software architecture, the publish–subscribe pattern (pub/sub) is a messaging pattern in which message senders, called publishers, categorize messages into classes (or topics), and send them without needing to know which components will receive them. Message recipients, called subscribers, express interest in one or more classes and only receive messages in those classes, without needing to know the identity of the publishers.

Source: Wikipedia — Publish–subscribe pattern (CC BY-SA 4.0)