To me, curing time is how long it takes for the coating to set-up after it's been applied and buffed off. For sealants and waxes, this is usually 24 hours. It varies for ceramic coatings between 4 to 48 hours.
In other words, it's best to not wash a car or apply a different kind of product until after the first finish product has cured. This is especially true if you're trying to build-up layers of traditional car wax (such as the Collinite paste waxes). Not long ago, I called the folks at Collinite, spoke with one of the family owners and had a nice discussion about this. I shared my observations with him and since he knows the chemical make-up of the products, he agreed completely (and actually took some notes on my techniques).
Ray