preserver vs shielder

preserver and shielder both are nouns.

Word	Noun	Adjective	Verb	Adverb
preserver	Yes	No	No	No
shielder	Yes	No	No	No

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

Other hyponyms of preserver include defender, guardian, protector.

preserver (noun)	shielder (noun)
rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning	a person who cares for persons or property
a skilled worker who is employed to restore or refinish buildings or antique furniture
someone who keeps safe from harm or danger
a cook who preserves fruits or meat