Activity Tracking: Monitors steps, calories, distance, heart rate, sleep, GPS, blood oxygen, fall detection. Supports a variety of workouts like running, cycling, yoga and swimming.
Temperature Sensor: Added on Series 8 and 9
Notifications: Displays notifications from your phone.
Water Resistant: Yes

Activity Tracking: Monitors steps, active minutes and sleep, and offers games and challenges Sends activity and chore reminders.
Water resistant: No