Step aerobics is a classic cardio workout. It's lasted for decades for a simple reason: It delivers results.
The "step" is a 4-inch to 12-inch raised platform. You step up, around, and down from the platform in different patterns to boost your heart rate and breathing, and strengthen your muscles.
Step aerobics moves range from simple to advanced. The most basic is a step-up, step-down. Once you get more experienced, you do moves that take you over the top and around the step forwards, sideways, and backwards.