carambola vs fruit tree

carambola and fruit tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
carambola	Yes	No	No	No
fruit tree	Yes	No	No	No

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

carambola (noun)	fruit tree (noun)
deeply ridged yellow-brown tropical fruit; used raw as a vegetable or in salad or when fully ripe as a dessert	tree bearing edible fruit
East Indian tree bearing deeply ridged yellow-brown fruit