We will talk all about diffusion. Diffusion id the spread of a phenomenon from the hearth outward. Relocation and expansion are two types of diffusion. Relocation diffusion is caused because of the movement of people, while in expansion diffusion, there is an increase in the number of people adapting this new phenomenon. We will also discuss the different types of expansion diffusion and their specific example. We will also talk about how colonialism and imperialism cause diffusion and how it has shaped our modern world. We will also discuss the many social reactions that are caused by the diffusion of culture.