What are promises and observables?

Related questions

1. Why do we need promises in node JS?
2. Is async await better than promises?
3. What is difference between for while and do while loop?
4. What is the difference between the while and do while statements?
5. What is async in node JS?
6. What does async stand for?
7. What the heck is a callback?
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Tags

1. #matter
2. #doesn
3. #events
4. #observable
5. #event
6. #features
7. #preferred
8. #promise
9. #handle
10. #often
11. #provides
12. #where
13. #stream
14. #callback
15. #multiple
16. #because
17. #called
18. #allows
19. #languages