Property binding is used to bind an element's property to the component data. You use property binding by surrounding the property with square brackets and have the expression as a standard value assignment:
<app-category-menu [items]="menuItems"></app-category-menu>
In the preceding example, the component view binds a menuItems field or property in its component state to the items property of app-category-menu. When menuItems changes in the component, so does the bound items property of the child component.