A terraced or terrace house (UK) or townhouse (US) is a term in architecture and city planning referring to a style of medium-density housing that originated in Europe in the 16th century, where a row of identical or mirror-image houses share side walls. They are also known in some areas as row houses or linked houses.Terrace housing can be found throughout the world, though it is in abundance in Europe and Latin America, and extensive examples can be found in North America and Australia.