So now how about listening to events on the host element that wraps the component’s template? How can we do that properly in Angular apps? That’s the very question we will answer in this article. Before diving directly into listening to DOM events on a host element, I think we need to touch on what a host element is. The concept of host element applies not only to components but also attribute directives.
Source: Four ways of listening to DOM events in Angular (Part 2: @HostListener)