Answer
A biodiversity hotspot is an area with an exceptional level of biodiversity whose continued existence is threatened.
Work Step by Step
There is a specific set of biodiversity hotspots designated worldwide. They make up an extremely small total area, but hold a majority of the world's diversity of species.
Due to the small size and inherently fragile nature of these ecosystems, they are easily damaged. The current hotspots each sit at a fraction of their original size and continue to diminish under the threat of human intervention and climate change.