Been working with Angular for awhile and wanted to get down some detail on the differences between Observable vs Subject vs BehaviorSubject. It's a bit of a mind shift but well worth the effort.
To that end I find it's best to get hands on so here's the example running on stackblitz. stackblitz.com is a excellent resource for Angular, React and Ionic code editing / sharing.
Example uses Observable.from() to show how a subscription can be made to retrieve all values, in sequence, from an array on subscription.
Example shows usage of Subject to receive events, best used where there are multiple subscribers. Subject emits value on next call only.
Example shows usage of BehaviorSubject to receive events, best used where you need the current value on subscription.
Next up forkJoin and mergeMap...