High-temperature superconductors are materials that can conduct electricity without resistance at relatively high temperatures, typically above the boiling point of liquid nitrogen (-196°C). This property allows them to carry electrical currents more efficiently than traditional superconductors, which require much colder conditions to function. These materials often contain complex compounds, such as copper oxides, and are used in various applications, including magnetic resonance imaging (MRI) and particle accelerators. The discovery of high-temperature superconductors in the 1980s has spurred ongoing research to understand their mechanisms and to develop new materials with even higher critical temperatures.