Promisehandles a single event when an async operation completes or fails.
So, a promise doesn't handle anything - a promise is just a value over time. The charactaristics of promises are that:
- Because a promise is just a value - promises are multicast which means multiple
.thens are 'transparent'.
- Native promises are what async functions return and what they
- Promises have three states (fulfilled, pending and rejected) and transition between them just once.