Jaccard Index

The Jaccard Index is a way to measure how similar two sets are. It compares the number of items they share to the total number of items in both sets combined. Specifically, you count the common items (intersection) and divide that by the total unique items across both sets (union). The result is a number between 0 and 1: 0 means no overlap, and 1 means the sets are identical. It's commonly used in data analysis, search algorithms, and comparing similarities between things like documents, images, or groups.