Dr. Abhishek explained that a ventilator is a machine that supports or completely takes over the process of breathing for patients who are unable to breathe adequately on their own. It delivers oxygen into the lungs and removes carbon dioxide, thereby maintaining essential gas exchange when the body fails to do so naturally. Ventilators are lifesaving in conditions such as severe pneumonia, acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD) exacerbations, an