A ventilator is a medical device that helps people breathe when they are unable to do so on their own. It delivers oxygen to the lungs and removes carbon dioxide, which is essential for patients with severe respiratory issues, such as those suffering from COVID-19 or pneumonia. Ventilators can be used in hospitals or emergency situations to support patients until they can breathe independently again. These machines can be adjusted to provide different levels of support based on a patient's needs. Medical professionals, like doctors and nurses, monitor the ventilator settings closely to ensure the patient receives the right amount of air and oxygen.