Is <ion-app></ion-app> selector attached to the component in app.ts?

So I’ve just started working with Ionic 2 because I prefer working with Angular 2 over 1. I’m use the sidemenu starter layout, and wanted to implement some things I’ve worked on for another project, but I’m confused as to why the app.ts file in the apps folder doesn’t have a selector attached to it. My only thoughts are that it must be using the selector in the title. I’m going to test it out right now to confirm, but if anyone could direct me to the answer or where I can find it I would appreciate it.