The variety of species and habitats within an ecosystem and the genetic variability within a species or population.

In its most general sense, biodiversity refers to all aspects of variety in the living world. Specifically, the term may be used to describe the number of species, the amount of genetic variation or the number of community types present in an area.

The variability among living organisms on the earth, including the variability within and between species and within and between ecosystems.

The variation in life on Earth reflected at all levels from various ecosystems and species to the genetic variation within a species.

the total numbers of kinds of organisms on earth

the number and types of organisms in a region or environment.

the number of different kinds of organisms occurring in a particular place