tongs vs coal tongs

tongs and coal tongs both are nouns.

Word	Noun	Adjective	Verb	Adverb
tongs	Yes	No	No	No
coal tongs	Yes	No	No	No

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

tongs: any of various devices for taking hold of objects; usually have two hinged legs with handles above and pointed hooks below
coal tongs: tongs for taking hold of burning coals

Other hyponyms of tongs include fire tongs, ice tongs.

tongs (noun)	coal tongs (noun)
any of various devices for taking hold of objects; usually have two hinged legs with handles above and pointed hooks below	tongs for taking hold of burning coals