Fréchet distance

The Fréchet distance is a measure of the similarity between two curves in a metric space, often used in the context of comparing shapes or trajectories. It is conceptually similar to the more familiar Euclidean distance, but it takes into account the traversal of the curves themselves, which can be thought of as a "path" distance. To understand the Fréchet distance, imagine two people walking along two separate paths (curves). Each person can decide how quickly to walk along their respective path.