There are three main differences in land that can be invested in.
Green Belt Land is a planning policy tool which aims to prevent urban sprawl by keeping land permanently open. Generally, Green Belt comprises countryside which is used for agriculture, forestry or other similar open uses. When defined, Green Belt can shape patterns of development and ensure that development occurs at locations which have been allocated by local planning authorities. However, the boundaries of the Green Belt can exceptionally be changed to, for example, meet future development needs.
Greenfield Land is land that has not previously been developed. It includes forestry, agricultural land, and associated buildings that have been blended into the natural landscape.
Brownfield Land or previously developed land is land which is or was occupied by a permanent structure, including the curtilage of the developed land and any associated fixed surface infrastructure. There is, however, no presumption that land which has been previously developed is necessarily suitable for housing development nor that the whole of the curtilage should be developed.