Angular6

Structural Directives

https://angular.io/guide/structural-directives#template-input-variable

There are two other kinds of Angular directives, described extensively elsewhere: (1) components and (2) attribute directives.

A component manages a region of HTML in the manner of a native HTML element. Technically it's a directive with a template.

An attribute directive changes the appearance or behavior of an element, component, or another directive. For example, the built-in NgStyle directive changes several element styles at the same time.

You can apply many attribute directives to one host element. You can only apply one structural directive to a host element.