The framework consists of several libraries, some of them core and some optional.
main.ts- this file contain the bootstraping to start and intitialize the Angular Js application
app.module.ts- this file contains NgModule which has the routing concept and the new created component refrence, If any new component created, the refrence should be added here for initialization
app.component.ts- this file is the user defined angular js 2 component
index.html- the main page to load it.