sparkling water vs seltzer

sparkling water and seltzer both are nouns.

Word	Noun	Adjective	Verb	Adverb
sparkling water	Yes	No	No	No
seltzer	Yes	No	No	No

As nouns, sparkling water and seltzer are synonyms defined as:

sparkling water and seltzer: effervescent beverage artificially charged with carbon dioxide

Other synonyms of sparkling water include carbonated water, club soda, soda water.

sparkling water (noun)	seltzer (noun)
effervescent beverage artificially charged with carbon dioxide	naturally effervescent mineral water
	effervescent beverage artificially charged with carbon dioxide