This document discusses engine governors, which are devices that regulate the speed of engines. It provides several key points about governors: 1. Governors automatically maintain the uniform speed of an engine within specified limits when the load varies. 2. Governors regulate fuel supply to the engine based on load requirements to keep the mean speed consistent. 3. There are different types of governors, including centrifugal, inertia, hydraulic, pneumatic, electromechanical, and electronic governors.