Similarity

The concept of similarity plays a much more central role in modern AI systems than many people initially realize. Search engines, recommendation systems, document matching, semantic retrieval, and clustering all rely on the question: “which example is closest to which?” Similarity is not limited to surface-level matching; semantic, structural, and functional closeness can also matter. In embedding-based systems especially, high-quality similarity measurement directly affects product success. In short, similarity is not just a mathematical metric, but an invisible foundation of many AI experiences.