This document discusses Honda's VTEC (Variable Valve Timing and Lift Electronic Control) system. VTEC improves engine efficiency by using two camshaft profiles and electronically selecting between them. It was invented by Honda engineer Ikuo Kajitani and introduced in the 1980s. The system uses hydraulically actuated pins to switch between cam lobes, allowing for variable valve timing and lift. VTEC provides benefits like better fuel efficiency, torque and power while reducing emissions.