What is the difference between apt get update and upgrade?

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Tags

1. #updating
2. #about
3. #install
4. #installs
5. #updates
6. #their
7. #actually
8. #lists
9. #packages
10. #manager
11. #versions
12. #upgrade
13. #available
14. #package
15. #newer
16. #knows
17. #update
18. #after
19. #installed
20. #software