What is the difference between declarations, providers, and import in NgModule?

Question

I am trying to understand Angular (sometimes called Angular2+), then I came across @Module:

1. Imports

2. Declarations

3. <

Answer 1

Adding a quick cheat sheet that may help after the long break with Angular:

---

DECLARATIONS

Example:

declarations: [AppComponent]

What can we inject here? Components, pipes, directives

---

IMPORTS

Example:

imports: [BrowserModule, AppRoutingModule]

What can we inject here? other modules

---

PROVIDERS

Example:

providers: [UserService]

What can we inject here? services

---

BOOTSTRAP

Example:

bootstrap: [AppComponent]

What can we inject here? the main component that will be generated by this module (top parent node for a component tree)

---

ENTRY COMPONENTS

Example:

entryComponents: [PopupComponent]

What can we inject here? dynamically generated components (for instance by using ViewContainerRef.createComponent())

---

EXPORT

Example:

export: [TextDirective, PopupComponent, BrowserModule]

What can we inject here? components, directives, modules or pipes that we would like to have access to them in another module (after importing this module)