The VersaClimber mimics what it's like to vertically climb up something. To start, you grasp onto the upper handles with your hands and put your feet onto two steps. From there you work against the resistance to push and pull your hands and legs up and down.
At my gym, I always see the fittest looking people working out on the VersaClimber, and I do mean working out. By the time they get off of it, they're usually dripping in sweat and out of breath. It's a great machine for interval training, gives you one hell of a cardio workout, and strengthens both your upper and lower body.