Terminal illness:
Refers to an illness or condition that is incurable and irreversible. When a person is diagnosed as terminally ill, death is expected in a relatively short period of time.
Ventilator:
A machine that helps a patient breathe. Sometimes it is used temporarily until a person can breathe on his or her own; other times it is a permanent breathing aide. In the latter case, a tube is often placed directly into a patient's windpipe via a procedure called a tracheotomy.