Observable

In reactive-programming, observable are things that Observer subscribes to

Hot, Cold and Connectable observable

• Hot: immediately begin to emit the item as soon as it's created.
  • The observer that subscribe to this observable may start observing the sequence somewhere in middle
• Cold: wait for the observer to subscribe to it before emitting the items
  • These observer are guaranteed to see the item from the beginning.
• Connectable observer: these observers does not begin to emits item until its Connect method is called weather or not you have any observers subscribe to it.

note

Observable doesn't support BackPressure. For BackPressure support, use Flowable