Whats the difference in the Apple Watch 3 and 4?

Related questions

1. Can you text on the Apple Watch Series 1?
2. Will a 42mm band fit a 38mm Apple Watch?
3. Can Apple watch receive calls?
4. Why did my Apple Watch call 911?
5. Can all Apple watches make phone calls?
6. Can I swim with an Apple watch?
7. Does Apple watch track sleep?
8. Does Apple Watch have Internet?
9. Is there Siri on Apple Watch?
10. Does Siri make noise on Apple Watch?

Tags

1. #series
2. #optical
3. #features
4. #hardware
5. #called
6. #built
7. #faster
8. #claimed
9. #extras
10. #upgraded
11. #processor
12. #watch
13. #apple
14. #sensor
15. #heart
16. #altimeter
17. #barometric
18. #including
19. #times