Discussion on: Explain Futures and Streams in Dart like I'm Five

TL/DR:

Futures are like Promises. In fact, when Dart compiles into JavaScript, Futures are replaced with Promises.

Streams are essentially a subscription event handler.

In AngularDart, I'll use a Stream in a component like this:

  @Output()
  Stream<bool> get onButtonClose => _onButtonClose.stream;
  final StreamController<bool> _onButtonClose = new StreamController<bool>.broadcast();

And in the component's element I'll wrap an attribute of the same name as the variable tagged with the @Output annotation in parentheses:

<component (onButtonClose)="closeUI($event)"></component>

This means when the Stream has an event, it will trigger the closeUI() function and pass the event object as a parameter. Note: The Stream is set to pass objects of type bool (Stream<bool>), so the closeUI function must accept bool as a parameter.

That's the basics, but not for a five year old.

So let me go simpler:

A Future is something you can hold onto until the thing you actually want is available.

A Stream is a subscription, whenever something of interest is available, it will be passed through the Stream.