Christaller's Central Place Theory is a geographical theory that explains the size and spacing of human settlements based on economic principles. It suggests that settlements are arranged in a hexagonal pattern, with larger central places serving smaller surrounding areas.
The theory was applied in southern Germany, where it emerged. It has also been used to explain the distribution of cities in Midwest USA, revealing patterns of settlements and market areas.
Influences urban planning by predicting where central places (towns/cities) should be located to provide services efficiently. It affects economic development by guiding the placement of infrastructure and resources.