Bootstrap and entry components

The bootstrap property defines the components that are instantiated when a module is bootstrapped. First, Angular creates a component factory for each of the bootstrap components. And then, at runtime, it'll use the factories to instantiate the components.

To generate less code, and, as a result, to produce smaller bundles, Angular won't generate component factories for any components of TalksModule. The framework can see their usage statically, it can inline their instantiation, so no factories are required. This is true for any component used statically (or declaratively) in the template.

For instance, let's look at TalkCmp:

@Component({
  selector: 'talk-cmp',
  template: `
    {{talk.title}} {{talk.speaker}}
    {{talk.rating | formatRating}}
    <watch-button [talk]="talk"></watch-button>
    <rate-button [talk]="talk">...