What are promises and observables in angular?

Related questions

1. What does a promise return?
2. What is the difference between an observable and a promise?
3. What is a fetch promise?
4. What is the difference between put and post?
5. Does .then return a promise?
6. What is JSON request and response?
7. What is meant by Promise in Angularjs?
8. What is the difference between callbacks and promises?
9. What is protractor promise?
10. What is the significance of promise?

Tags

1. #promises
2. #there
3. #callback
4. #between
5. #permits
6. #observables
7. #differences
8. #finishes
9. #event
10. #promise
11. #every
12. #fails
13. #activity
14. #single
15. #observable
16. #stream
17. #async
18. #emits
19. #where
20. #languages
21. #least
22. #required
23. #events