Usually it is a townhouse or condo in a regular community neighborhood that is owned by a business that then sells "weeks" to other families for use on their annual vacation. From there in most agreements the family that bought the interest can rent their time to others. Disney has one that is run a bit differently, as instead of buying weeks or days you buy points, and depending on the time of year, size of room and location of the resort nights will cost a different number of points each night. It has been a great deal for us, made it possible for us to visit WDW each year since we purchased.