Biological diversity – or biodiversity – is the term given to the variety of life on Earth. It is the variety within and between all species of plants, animals and micro-organisms and the ecosystems within which they live and interact.

Biodiversity is the variability among living organisms from all sources, including terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species, and of ecosystems.
Biodiversity forms the foundation of the vast array of ecosystem services that critically contribute to human well-being.
Biodiversity is important in human-managed as well as natural ecosystems.
Decisions humans make that influence biodiversity affect the well-being of themselves and others.