Directives are instructions in the DOM just like the components that are kind of instructions in the DOM but with a template.
We typically add directives with an attribute selector, but technically the selector of a directive can be configured just like the selector of a component,
In Angular we have some built in directives and they can be split into 2 categories:
- Structural Directives: NgIf, NgSwitch and NgFor.
- Attribute Directives: NgClass, NgStyle and NgModel.