A house is a building that functions as a home, ranging from simple dwellings such as rudimentary huts of nomadic tribes and the improvised shacks in shantytowns to complex, fixed structures of wood, brick, concrete or other materials containing plumbing, ventilation and electrical systems. Houses use a range of different roofing systems to keep precipitation such as rain from getting into the dwelling space. Houses may have doors or locks to secure the dwelling space and protect its inhabitants and contents from burglars or other trespassers. Most conventional modern houses in Western cultures will contain one or more bedrooms and bathrooms, a kitchen or cooking area, and a living room. A house may have a separate dining room, or the eating area may be integrated into another room. Some large houses in North America have a recreation room. In traditional agriculture-oriented societies, domestic animals such as chickens or larger livestock (like cattle) may share part of the house with humans. The social unit that lives in a house is known as a household.
Most commonly, a household is a family unit of some kind, although households may also be other social groups, such as roommates or, in a rooming house, unconnected individuals. Some houses only have a dwelling space for one family or similar-sized group; larger houses called townhouses or row houses may contain numerous family dwellings in the same structure. A house may be accompanied by outbuildings, such as a garage for vehicles or a shed for gardening equipment and tools. A house may have a backyard or frontyard, which serve as additional areas where inhabitants can relax or eat.