What is the difference between Leisurely, Moderate and Advanced tours?

Tours labeled Leisurely are flat tours at an easy pace on bike paths free of motorized traffic. Tours labeled Leisurely-Moderate are flat tours on a mix of roads and bike paths. Tours labeled Moderate have some hilly terrain. Tours labeled Moderate-Advanced have more challenging terrain with a mix of hills, longer climbs and flat stretches. Their daily mileages tend to be longer than on our other tours.