breathing device vs ventilator

breathing device and ventilator both are nouns.

Word	Noun	Adjective	Verb	Adverb
breathing device	Yes	No	No	No
ventilator	Yes	No	No	No

As nouns, breathing device and ventilator are synonyms defined as:

breathing device and ventilator: a device that facilitates breathing in cases of respiratory failure

Other synonyms of breathing device include breathing apparatus, breathing machine.

breathing device (noun)	ventilator (noun)
a device that facilitates breathing in cases of respiratory failure	a device (such as a fan) that introduces fresh air or expels foul air
	a device that facilitates breathing in cases of respiratory failure