HVAC stands for Heating, Ventilation, and Air Conditioning. It is a system used to control the indoor climate of buildings, ensuring comfort by regulating temperature, humidity, and air quality. Heating systems warm the air during colder months, while air conditioning cools it during warmer months. Ventilation is crucial for maintaining fresh air circulation, removing indoor pollutants, and preventing moisture buildup. HVAC systems can be found in residential homes, commercial buildings, and industrial facilities, providing essential climate control for various environments. Proper maintenance of these systems is important for efficiency and longevity.