Navigable small world graphs are graph-based data structures designed to facilitate efficient approximate nearest neighbor search in high-dimensional vector and metric spaces. In these graphs, nodes represent data points and edges connect both locally adjacent elements and long-range shortcuts, reflecting the characteristics of small-world networks. This organization enables greedy routing algorithms to navigate large distances across the graph in early search phases using sparse long-range links, subsequently transitioning to dense local clusters to identify the closest neighbors. By balancing short average path lengths with high clustering coefficients, navigable small world graphs provide logarithmic or polylogarithmic search complexity without requiring exhaustive comparisons across the entire dataset.