life belt vs life ring

life belt and life ring both are nouns.

Word	Noun	Adjective	Verb	Adverb
life belt	Yes	No	No	No
life ring	Yes	No	No	No

As nouns, life belt and life ring are synonyms defined as:

life belt and life ring: a life preserver in the form of a ring of buoyant material

Other synonyms of life belt include life buoy, lifesaver.

life belt (noun)	life ring (noun)
a life preserver in the form of a ring of buoyant material	a life preserver in the form of a ring of buoyant material
belt attaching you to some object as a restraint in order to prevent you from getting hurt