An elliptical trainer is a cardio machine with two large pedals that go up and down in an circular motion. It is designed to mimic running on a treadmill or riding a bike, however, you use your feet to push the pedals which generates the resistance in the machine. Ellipticals tend to have static handles allowing you to hold on while you use the machine, giving you just a lower body workout. Cross trainers on the other hand use the same pedal motion, however the handles move alongside the pedals, giving you a full body workout.