Power system stability refers to the ability of an electrical power system to maintain a state of equilibrium during normal operating conditions and after being subjected to disturbances. These disturbances can include sudden changes in load, faults, or equipment failures. Stability ensures that the system can return to a steady state without losing power or causing widespread outages. There are different types of stability, including transient stability, which deals with the system's response to large disturbances, and voltage stability, which focuses on maintaining acceptable voltage levels. Ensuring power system stability is crucial for reliable electricity supply and the overall efficiency of the electric grid.