Air conditioning is a process that regulates the temperature, humidity, cleanliness, and circulation of air in a confined environment, usually indoors. In warmer climates or seasons, air is cooled and dehumidified, whereas in colder climates or seasons, air is heated and humidified. Air conditioning systems are widely utilized in residential, commercial, industrial, and institutional buildings, as well as automobiles and aircraft.

Ventilation technology describes the air supply in enclosed spaces. Contrary to air conditioning technology, no conditioning of the temperature and humidity takes place.