Distinctiveness is used in the context of Biodiversity Net Gain (BNG) to evaluate the quality and importance of different habitats. It provides a way to assess the ecological value of a habitat based on its unique characteristics. This assessment is essential for ensuring that biodiversity is maintained or enhanced through development projects.
The Biodiversity Metric Tool automatically assigns a distinctiveness category to each habitat based on the data collected. In other words, each habitat type has a fixed distinctiveness score.
You can read more about distinctiveness here.