What is the difference between Promises and Observables?

Question

What is the difference between Promise and Observable in Angular?

An example on each would be helpful in understanding both the cases. In w

Answer 1

1. a Promise is eager, whereas an Observable is lazy,
2. a Promise is always asynchronous, while an Observable can be either synchronous or asynchronous,
3. a Promise can provide a single value, whereas an Observable is a
   stream of values (from 0 to multiple values),
4. you can apply RxJS operators to an Observable to get a new tailored stream.