A food forest is a forest which is designed to mimic the nature forest, that is the nature forest that is native and or endemic to the location in which it is being planted. A food forest should include all forest layers and type on what is or was the nature forest for that area, usually 5 to 7 different layers. These forest layers are to be replaced with productive species (plant species that you want) as well as with supportive species (plants that support the productive plant species).
As a food forest mimics the nature or endemic forest of an area a food forest can look vastly different from climate to climate and continent to continent.