What is the difference between a Observable and a Subject in rxjs?

Question

i was going through this blog and to read about Observables and i couldnt figure out the difference between the Observable and a Subject

Answer 1

From another perspective, it is good to note that the subscription to an Observable re-execute the Observable function. This can lead performance issue if the data source is a service for instance.

If you want several subscribers to get the same value, you may need a Subject. For this, make sure that your subscription is set before the Subject subscribed to the data source. Otherwise, your process would be stuck.

More details here: https://javascript.tutorialhorizon.com/2017/03/23/rxjs-subject-vs-observable/