Question: what is the difference between the fitbit charge 2 and charge 3?
Answer: The Fitbit Charge 2 has a heart rate monitor, step and calorie tracking, sleep tracking and multi-sport tracking, so you can actually track your workouts. It can also automatically detect exercise, so you won't need to manually enable most modes. The Fitbit Charge 3 has all that but also adds to and improves on it.