GLB is a compact, binary 3D file format — the binary form of glTF (GL Transmission Format) — that stores 3D models, geometry, materials, textures, and animations together in a single self-contained file. GLB files are widely used because they are smaller and faster-loading than formats like OBJ or FBX, with embedded data that makes them ideal for web, AR, and realtime 3D previews across browsers and engines like Blender, Unity, and Three.js.