When the computer receives a rich signal (high voltage) from the O2 sensor, it leans the fuel mixture to reduce the sensor's reading. When the O2 sensor reading goes lean (low voltage), the computer reverses again making the fuel mixture go rich.
Chemistry and physics are branches of science that both study matter. The difference between the two lies in their scope and approach. Chemists and physicists are trained differently, and they have different professional roles, even when working in a team.
Chemistry is the science of chemical elements and compounds. Chemistry is a branch of science that deals with chemical elements and compounds, and how these things work together. It is the study of the materials (things) that make up our bodies and everything in the world around us.