froth vs soapsuds

froth and soapsuds both are nouns.

Word	Noun	Adjective	Verb	Adverb
froth	Yes	No	Yes	No
soapsuds	Yes	No	No	No

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

Other hyponyms of froth include shaving foam, head, lather, lather, suds, spume, white water, whitewater.

froth (noun)	soapsuds (noun)
a mass of small bubbles formed in or on a liquid	the froth produced by soaps or detergents

froth (verb)	soapsuds (verb)
exude or expel foam
become bubbly or frothy or foaming
make froth or foam and become bubbly