Vector quantization maps high-dimensional vectors to codewords from a finite codebook. Each codeword is the center of a Voronoi region that contains all vectors closest to that codeword. The LBG algorithm trains a vector quantizer by iteratively adjusting codewords to minimize distortion based on a training set. Tree-structured vector quantization further improves efficiency by recursively partitioning the codebook into binary tree structure to reduce distance comparisons at the cost of potential increases in distortion and storage requirements for additional test vectors.