preserver vs life belt

preserver and life belt both are nouns.

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

As nouns, life belt is a hyponym of preserver; that is, life belt is a word with a more specific, narrower meaning than preserver:

preserver: rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning
life belt: a life preserver in the form of a ring of buoyant material

Other hyponyms of preserver include life buoy, life ring, lifesaver, cork jacket, life jacket, life vest, water wings.

preserver (noun)	life belt (noun)
rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning	a life preserver in the form of a ring of buoyant material
a skilled worker who is employed to restore or refinish buildings or antique furniture	belt attaching you to some object as a restraint in order to prevent you from getting hurt
someone who keeps safe from harm or danger
a cook who preserves fruits or meat