breathing apparatus vs ventilator

breathing apparatus and ventilator both are nouns.

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

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

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

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

breathing apparatus (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