I want to know what is the differences between a ventilator, and a non-invasive ventilator?

How it is delivered. A ventilator is a machine to deliver air with oxygen to a patient's lungs. It can deliver this air/oxygen mixture either by a tube in the throat, whereby it is called invasive ventilation. If the air/oxygen mixture is delivered by a tight-fitting mask, then it is non-invasive ventilation. What is "invading" the patient is the delivery device. Both are effective.