Combustion systems are processes that involve the burning of fuel to produce energy. This energy can be used for various applications, such as heating, electricity generation, and powering engines. Common fuels include natural gas, coal, and oil, which react with oxygen in the air to release heat and light. The combustion process typically occurs in a controlled environment, such as a furnace or engine, where the fuel is mixed with air and ignited. Efficient combustion systems minimize waste and emissions, contributing to cleaner energy production. Technologies like catalytic converters and flue gas treatment help reduce harmful byproducts from combustion.