I see some question/answers relating to Rx Subscriptions/Observers but they may be for older versions of Rx and also not for RxJS, which may conform to a different API.

I was under the impression that subscriptions/subscribers and observers were all the same. If you look at the docs, they are in different adjacent sections, but seem to be exactly the same:

Observer:
<http://reactivex.io/rxjs/manual/overview.html#observer>

Subscription:
<http://reactivex.io/rxjs/manual/overview.html#subscription>

what the heck is the difference? Can someone given an example with a practical difference between the two?