`RouterEvents` is a utility service to provide an easy implementation for one of the most frequent needs in Angular templates: `TrackByFunction`. Please see [this page in Angular docs](https://angular.io/guide/template-syntax#ngfor-with-trackby) for its purpose.
`RouterEvents` is a utility service for filtering specific router events and reacting to them. Please see [this page in Angular docs](https://angular.io/api/router/Event) for available router events.