necklace vs choker

necklace and choker both are nouns.

Word	Noun	Adjective	Verb	Adverb
necklace	Yes	No	No	No
choker	Yes	No	No	No

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

necklace: jewelry consisting of a cord or chain (often bearing gems) worn about the neck as an ornament (especially by women)
choker: necklace that fits tightly around a woman's neck

Other hyponyms of necklace include chain, strand, string, chain, collar, dog collar, neckband.

necklace (noun)	choker (noun)
jewelry consisting of a cord or chain (often bearing gems) worn about the neck as an ornament (especially by women)	a high tight collar
	necklace that fits tightly around a woman's neck
	someone who kills by strangling
	an unfortunate person who is unable to perform effectively because of nervous tension or agitation