Are the Final Fantasy games connected?

Related questions

1. What is Crysta Ffxiv?
2. What is the story of Final Fantasy 15?
3. Is Final Fantasy 15 finished?
4. Is Final Fantasy 15 a sequel?
5. Who is Noctis mother?
6. Will FFXV have a sequel?
7. How many World of Warcraft games are there?
8. Does Nintendo own Final Fantasy?
9. Can you play Final Fantasy 15 without playing the others?

Tags

1. #storywise
2. #spawned
3. #connected
4. #direct
5. #fantasy
6. #sequels
7. #spinoffs
8. #seperate
9. #completely
10. #other
11. #universes
12. #numbers
13. #unconnected
14. #games
15. #final