snail vs Helix pomatia

snail and Helix pomatia both are nouns.

Word	Noun	Adjective	Verb	Adverb
snail	Yes	No	Yes	No
Helix pomatia	Yes	No	No	No

As nouns, Helix pomatia is a hyponym of snail; that is, Helix pomatia is a word with a more specific, narrower meaning than snail:

snail: freshwater or marine or terrestrial gastropod mollusk usually having an external enclosing spiral shell
Helix pomatia: one of the chief edible snails

Other hyponyms of snail include scorpion shell, edible snail, garden snail.

snail (noun)	Helix pomatia (noun)
freshwater or marine or terrestrial gastropod mollusk usually having an external enclosing spiral shell	one of the chief edible snails
edible terrestrial snail usually served in the shell with a sauce of melted butter and garlic

snail (verb)	Helix pomatia (verb)
gather snails