ranch hand vs cowherd

ranch hand and cowherd both are nouns.

Word	Noun	Adjective	Verb	Adverb
ranch hand	Yes	No	No	No
cowherd	Yes	No	No	No

As nouns, cowherd is a hyponym of ranch hand; that is, cowherd is a word with a more specific, narrower meaning than ranch hand:

ranch hand: a hired hand on a ranch
cowherd: a hired hand who tends cattle and performs other duties on horseback

Other hyponyms of ranch hand include cowhand, cowpoke, cowpuncher, puncher.

ranch hand (noun)	cowherd (noun)
a hired hand on a ranch	a hired hand who tends cattle and performs other duties on horseback