A basic tracker shows you the steps you’ve taken, the distance you’ve traveled, the calories you’ve burnt as well as measuring your sleep quality.
It then syncs with your phone and puts all of the interesting data in an easy-to-read image.
Trackers are compatible with iphones and androids - for the most part.
The expensive trackers also keep track of your heart rate, so they’re considered to be more advanced.
But the priciest of them all have GPS and can track your altitude and location with a GPS.