breathing apparatus vs breathing machine

breathing apparatus and breathing machine both are nouns.

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

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

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

Other synonyms of breathing apparatus include breathing device, ventilator.

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