Base isolation is a seismic design technique used to protect buildings from earthquake forces. It involves placing a structure on flexible bearings or isolators that allow it to move independently from ground motion. This reduces the amount of energy transferred to the building during an earthquake, minimizing damage. The isolators can be made from materials like rubber or steel and are designed to absorb and dissipate seismic energy. By using base isolation, engineers can enhance the safety and resilience of structures, such as hospitals, bridges, and schools, ensuring they remain functional after an earthquake.