This article describes the history of building types and styles—what things were built. See History of construction for the history of construction tools and techniques—how things were built. The history of architecture traces the changes in architecture through various traditions, regions, overarching stylistic trends, and dates. The beginnings of all these traditions is thought to be humans satisfying the very basic need of shelter and protection. The term "architecture" generally refers to buildings, but in its essence is much broader, including fields we now consider specialized forms of practice, such as urbanism, civil engineering, naval, military, and landscape architecture. Trends in architecture were influenced, among other factors, by technological innovations, particularly in the 19th, 20th and 21st centuries. The improvement and/or use of steel, cast iron, tile, reinforced concrete, and glass helped for example Art Nouveau appear and made Beaux Arts more grandiose. Neolithic Architectural advances are an important part of the Neolithic period (10,000-2000 BC), during which some of the major innovations of human history occurred. The domestication of plants and animals, for example, led to both new economics and a new relationship between people and the world, an increase in community size and permanence, a massive development of material culture and new social and ritual solutions to enable people to live together in these communities. New styles of individual structures and their combination into settlements provided the buildings required for the new lifestyle and economy, and were also an essential element of change. Although many dwellings belonging to all prehistoric periods and also some clay models of dwellings have been uncovered enabling the creation of faithful reconstructions, they seldom included elements that may relate them to art. Some exceptions are provided by wall decorations and by finds that equally apply to Neolithic and Chalcolithic rites and art. In South and Southwest Asia, Neolithic cultures appear soon after 10,000 BC, initially in the Levant (Pre-Pottery Neolithic A and Pre-Pottery Neolithic B) and from there spread eastwards and westwards. There are early Neolithic cultures in Southeast Anatolia, Syria and Iraq by 8000 BC, and food-producing societies first appear in southeast Europe by 7000 BC, and Central Europe by c. 5500 BC (of which the earliest cultural complexes include the Starčevo-Koros (Cris), Linearbandkeramic, and Vinča). Neolithic settlements and "cities" include: Göbekli Tepe in Turkey, ca. 9,000 BC Jericho in the Levant, Neolithic from around 8,350 BC, arising from the earlier Epipaleolithic