angularjs2 common stuff that i always forgets
providers :  // providers
providers array provide a dependency injection layer between ngmodule and other child components. A child component will typically traverse to the parent to look for a provider - a singleton service or in plain language a class with a tasks like news feed service or http service.
if you specify providers in a child component, this service will be instantiated as a separate instance.
This module provides services for running and opening browser. What type of services?
Always import BrowerModule in the root AppModule.ts.
@Input and @Output
Passing data using @Input (Property passing with  ) and @Output (event passing with () )
You essentially can still create custom directive in Angular2.
@Pipe - custom, stateless and stateful pipe