The document discusses soft starters, which are electronic starters that control the voltage applied to three-phase induction motors during start up and shut down. Soft starters reduce mechanical and electrical stresses by gradually increasing voltage from 0% to 100% over an adjustable ramp time, rather than applying full voltage instantly. This allows the motor to accelerate smoothly and limits high starting currents that can damage equipment. Soft starters provide benefits like reduced component wear, maintenance needs, and power consumption compared to direct-on-line or star-delta starters.