When the user passes '/about' in the address bar of the browser appending to the end of the application URL, the router will match the request with the 'about' and initiate the AboutComponent to handle rendering the view for about. We need to somehow inform the router where to display this about view. This can be achieved by specifying <router-outlet/>, which is similar to the <ng-view/> tag in AngularJS 1.x to load the templates associated with the corresponding path of the route.
Router links help navigate the route URL via the link specified in the anchor tag by clicking on the router link. A sample router link tag is given here: