Distance Metric

A distance metric is a core tool used to measure how different two data points are. Clustering algorithms, nearest-neighbor methods, and many embedding-based systems rely on such measures. However, not every metric is appropriate for every problem. In some cases geometric closeness matters most, in others angular similarity, and in still others domain-specific measures are more meaningful. For that reason, choosing a distance metric may seem like a small detail, but it can significantly affect model behavior and output quality.