The Ventilator has represented an advance in the respiratory support for patients on anesthesia and intensive care. The ventilatory support increases the chance of survival in patients with respiratory failure, and / or major surgical procedures. This paper consists of a summary of advances in the ventilatory support, in describing the physiological mechanisms and especially the functioning of the main ventilation modalities. The limits of pressure, volume, PEEP, and the concepts of safe ventilation, Stress, Strain, are important for proper treatment. New ventilation modalities, despite not yet available in most health care units, are also described because of its great importance for better sync and fewer complications with the use of mechanical ventilation.