A ventilator is a machine that helps a person breathe. It is commonly used in the medical field as a form of life support for individuals who are unable to breathe adequately on their own due to various conditions such as respiratory failure, severe brain injury, or neuromuscular disorders.

The ventilator works by delivering a controlled flow of oxygen and/or air into the lungs, through a tube that is placed into the airway. The machine can be adjusted to provide different levels of pressure and support, based on the individual's needs.