Biodiversity is the variety of life in a place — not just “lots of animals”, but many kinds of plants, animals, fungi, and even the small differences inside one kind. A rainforest has high biodiversity. A parking lot has very little. People use it in news, school, and government reports. Though actually, it has become a feel-good word: a company may say they “support biodiversity” without saying which living things, or whether those things are still there. Scientists mean something you can try to count: how many kinds, how different they are, whether the web of life is still thick. Losing one famous animal is sad; losing biodiversity is the quieter thinning of the whole mix, including things nobody has a poster of.