Photochemical Smog: A type of smog formed by chemical reactions between sunlight and pollutants like nitrogen oxides (NOx) and volatile organic compounds (VOCs).
Tropospheric Ozone: Ozone found in the lower part of Earth's atmosphere where we live; it is different from stratospheric ozone which protects us from harmful UV radiation.
VOCs (Volatile Organic Compounds): Organic chemicals that easily evaporate into the air and can contribute to the formation of ground-level ozone.