A topological insulator is a special type of material that behaves as an insulator in its interior but conducts electricity on its surface. This unique property arises from the material's electronic structure, which is influenced by its topology, a branch of mathematics that studies shapes and spaces. The surface states of topological insulators are protected from impurities and defects, allowing for robust electrical conduction. These materials have potential applications in advanced technologies, such as quantum computing and spintronics. Researchers are exploring their use in devices that could lead to faster and more efficient electronics, leveraging the unique properties of topological insulators to create new functionalities.