What is HVAC System I Heating, Ventilation & Air Conditioning I Function

What is HVAC? An introduction is captured with meaning & function

HVAC means
H -- Heating
V -- Ventilation
AC -- Air Conditioning

Introduction: (0:00)
Definition: (0:38)
Heating : (1:02)
Ventilation : (3:47)
Air Conditioning: (5:07 )
Conclusion: (10:56)