Distance metric
A distance metric is a mathematical function that assigns a non-negative value to each pair of points in a given space, measuring the distance between them, and is a fundamental concept in Geometry, Topology, and Metric spaces. Distance metrics are used to define the notion of proximity and similarity between objects in various fields, including Physics, Computer science, and Engineering. The most common example of a distance metric is the Euclidean distance, which is used to measure the distance between two points in a Euclidean space. Other examples of distance metrics include the Manhattan distance and the Minkowski distance. Distance metrics play a crucial role in many applications, such as Clustering, Dimensionality reduction, and Nearest neighbor search.