Topological insulators are materials that behave as insulators in their interior but conduct electricity on their surfaces. This unique property arises from their electronic structure, which is influenced by the material's topology, or geometric arrangement. The surface states are protected from impurities and defects, allowing for robust electrical conduction. These materials have potential applications in electronics and quantum computing due to their ability to support spin-polarized currents. Researchers are exploring their use in devices like quantum computers and spintronics, which could lead to faster and more efficient technologies.