Observables are also like callbacks and promises - that are responsible for handling async requests. Observables are a part of the RXJS library.
import { Observable } from 'rxjs';
const observable = new Observable(subscriber => {
subscriber.next(1);
subscriber.next(2);
subscriber.next(3);
setTimeout(() => {
subscriber.next(4);
subscriber.complete();
}, 1000);
});
Observable Phases