Vegetation, in its most general biological meaning refers to the plant cover of the earth. Vegetation displays patterns that reflect a wide variety of environmental characteristics as well as temporal aspects operating on it. The vegetation itself is often a major factor defining the habitat for a wide range of plant and animal species. The survey and mapping of vegetation is seen as a baseline inventory to assist natural resource management.

Mapping vegetation is not an exact science, rather an applied science that imposes boundaries on a transition or continuum that is often temporal as well as spatial. The attempt is to capture unique map unit boundaries that are not always distinctly definable in nature. Map units can be defined as an assemblage of plant species which are discernable on an interpretive base (i.e. aerial photography, satellite imagery) and appear similar structurally and floristically and form repeatable units across the landscape.

A vegetation map is attributed with site based data where individual sites have been grouped based on structural characteristics and presence/absence of species. The groupings of sites are referred to as vegetation communities and are used to describe the map units defined on the interpretive base.