Exhaust emissions are gases and particles released into the air from the exhaust system of vehicles, such as cars and trucks. These emissions primarily come from the combustion of fuels like gasoline or diesel, and they can include harmful substances like carbon monoxide, nitrogen oxides, and particulate matter. Regulations often aim to reduce exhaust emissions to improve air quality and protect public health. Technologies such as catalytic converters and diesel particulate filters are commonly used in vehicles to minimize these harmful outputs, ensuring that they meet environmental standards set by organizations like the Environmental Protection Agency (EPA).