The term non-invasive is a technical term and it conveys the idea of a kind of treatment that doesn't involve cutting into the body of a patient.
Invasive is a term that we use to describe the phenomenon of attacking somebody and as usually a medical operation involves cutting into the body which literally is a kind of attack, so when you are using the term it says that you are not attacking the body of the person getting the treatment.
These days this kind of healing technique are more in use as they do not force the patient to get inactive after the operation and also it is believed as less costly that makes even the poor to get the benefit of the healthy life.
Invasive is a term that we use to describe the phenomenon of attacking somebody and as usually a medical operation involves cutting into the body which literally is a kind of attack, so when you are using the term it says that you are not attacking the body of the person getting the treatment.
These days this kind of healing technique are more in use as they do not force the patient to get inactive after the operation and also it is believed as less costly that makes even the poor to get the benefit of the healthy life.