NgModule

This module configures the injector and the compiler and helps organize the related thing. NgModule is a class marked as @NgModule. It contains some needed array which is used to kickstart the app or component and import external module to achieve the functionally.

declarations: [ ]: This array used to register a particular component with this module.

imports:[ ]: This array used to register other modules to achieve the functionally in this module or application wide.

providers: [ ]: This array is used to register the service, directives, and pipes which is available application wide.

bootstrap: [ ]: This array Kickstart the App Component. and tell the module which component is called now.