Biodiversity, which is short for biological diversity, is the term used to describe the whole variety of life on Earth. It doesn't just mean rare species, like giant pandas, areas of high species diversity, such as rainforests, big impressive creatures, like lions, or economically important species, like cod.
Biodiversity encompasses the diversity of all living things, from human beings to micro-organisms, the diversity of all the habitats in which they live and the genetic diversity of individuals within a species.
Biodiversity is the amazing richness and variety of wildlife and habitats on Earth, from snowfields to rainforests and from mountain tops to the deep ocean floor. Even in 21st-century Britain the range of biodiversity is extraordinary. In the busiest city park and the quietest rocky cove there is an enormous number of individual species, each one superbly adapted for its own environmental needs.
All of these are part of the global ecosystem - the Earth's entire collection of living things and the environment in which they live.