How is Debian different from Ubuntu?

Related questions

1. Is Linux the same as Unix?
2. Can Ubuntu run Debian packages?
3. Is Linux operating system free?
4. Can Debian use Ubuntu repositories?
5. How do I know if my OS is 32 or 64 bit Linux?
6. Is arm 32 or 64 bit?
7. Is Debian Testing stable enough?
8. Can Linux be installed on any computer?
9. Is Debian easy to use?
10. Is Debian unstable safe?

Tags

1. #these
2. #model
3. #stable
4. #between
5. #debian
6. #releases
7. #based
8. #ubuntu
9. #three
10. #testing
11. #differences
12. #obvious
13. #released
14. #different
15. #stability
16. #tierd
17. #insanely
18. #distributions
19. #unstable
20. #release