Homestay (also home stay and home-stay) is a form of hospitality and lodging whereby visitors share a residence with a local of the area (host) to which they are traveling. The length of stay can vary from one night to over a year and can be provided for free (gift economy), in exchange for monetary compensation, in exchange for a stay at the guest's property either simultaneously or at another time (home exchange), or in exchange for housekeeping or work on the host's property (barter economy). Homestays are examples of collaborative consumption and the sharing economy. Homestays are used by travelers; students who study abroad or participate in student exchange programs; and au pairs, who provide child care assistance and light household duties. They can be arranged via certain social networking services, online marketplaces, or academic institutions. Social networking services where hosts offer homestays for free are called hospitality exchange services.