Cultural diffusion is the spread of ideas between cultures through movement of people, goods, or ideas. There are two main types: expansion diffusion which strengthens in the origin, and relocation diffusion which physically moves an idea. Population growth is influenced by birth and death rates and stages of demographic transition. Rostow's model outlines five stages of economic growth through industrialization. Von Thünen analyzed how distance from markets influences land use patterns. Core-periphery and dependency theories address global economic disparities.