House sitting (or bedsitting) is the practice whereby a landlord (or "homeowner"), leaving his house for a period of time, entrusts it to one or more "house sitters", who by a mutual agreement are entitled to live there rent-free in exchange for assuming responsibilities such as taking care of the homeowner's pets, performing general maintenance (including pools, lawns, air-conditioning systems etc.), keeping trespassers off the property, readdressing the mail, and in general, making sure that everything runs smoothly just as if the owner were at home.
It is also generally implied that crime is deterred by the presence of the house sitter.
The whole practice is open to negotiation, notably as to whether a security deposit is required by the homeowner and whether a money payment should be made from one of the parties involved (as its share of the benefits is larger: typically, this is considered to be the house sitter).
Often, pet sitters simultaneously assume the role of a house sitter while they are caring for a homeowner's pet. This may or may not increase the pet sitter's standard rate, depending on the individual and the amount of tasks required.
Usually these sites require a membership fee from either the would-be house sitter, the homeowner or both, and provide a basic infrastructure to allow contacts between potential house sitters and homeowners