Frage im Vorstellungsgespräch bei Philips

They asked me AJAX( using plain JS ), Angular Dependency Injection ( How does it works ), Write Service and component and inject a service inside a component.What design pattern does a service has. Can we store the Login and password using any angular module while authorizing an user from user Login page . He had given me a scenario. First upload a file and then show the upload is complete notification in html page. he asked how do you do it?