cask vs keg

cask and keg both are nouns.

Word	Noun	Adjective	Verb	Adverb
cask	Yes	No	No	No
keg	Yes	No	No	No

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

Other hyponyms of cask include beer barrel, beer keg, butt, hogshead, pickle barrel, shook, tun, wine barrel, wine cask.

cask (noun)	keg (noun)
a cylindrical container that holds liquids	small cask or barrel
the quantity a cask will hold	the quantity contained in a keg