breathing device vs breathing machine

breathing device and breathing machine both are nouns.

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

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

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

Other synonyms of breathing device include breathing apparatus, ventilator.

breathing device (noun)	breathing machine (noun)
a device that facilitates breathing in cases of respiratory failure	a device that facilitates breathing in cases of respiratory failure