Anil Singh | Code-sample.com

Both promise & observable help us to asynchronous requests callback. The important differences are: Promise Angular 2 promises handle a single callback when an async requests callback completes or fails. Observable Angular 2 provides a new pattern for running asynchronous requests, called Observables. Angular 2 uses an analogous pattern called Observables. The Observable classes in Angular 2 are provided by the ReactiveX library. Angular 2 observable allows passing zero or more events where the callback is called for each event. Observable provides operators like map , forEach etc. Reference link. https://egghead.io/lessons/rxjs-rxjs-observables-vs-promises