Pyrus communis vs fruit tree

Pyrus communis and fruit tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pyrus communis	Yes	No	No	No
fruit tree	Yes	No	No	No

As nouns, fruit tree is a hypernym of Pyrus communis; that is, fruit tree is a word with a broader meaning than Pyrus communis:

Pyrus communis: Old World tree having sweet gritty-textured juicy fruit; widely cultivated in many varieties
fruit tree: tree bearing edible fruit

Pyrus communis (noun)	fruit tree (noun)
Old World tree having sweet gritty-textured juicy fruit; widely cultivated in many varieties	tree bearing edible fruit