Organoids and 3D stem cell cultures represent a significant advancement in modeling human development and disease. These miniaturized, self-organizing structures mimic the architecture and function of real organs, offering more accurate insights than traditional 2D cultures. Derived from stem cells, organoids are used in drug testing, disease modeling, and personalized medicine. 3D cultures enhance cell-to-cell interactions and tissue complexity, closely replicating in vivo conditions. This technology is transforming biomedical research and accelerating regenerative therapies.