future perfect vs perfect tense

future perfect and perfect tense both are nouns.

Word	Noun	Adjective	Verb	Adverb
future perfect	Yes	No	No	No
perfect tense	Yes	No	No	No

As nouns, perfect tense is a hypernym of future perfect; that is, perfect tense is a word with a broader meaning than future perfect:

future perfect: a perfective tense used to describe action that will be completed in the future
perfect tense: a tense of verbs used in describing action that has been completed (sometimes regarded as perfective aspect)

Other hypernyms of future perfect include perfect, perfective, perfective tense.

future perfect (noun)	perfect tense (noun)
a perfective tense used to describe action that will be completed in the future	a tense of verbs used in describing action that has been completed (sometimes regarded as perfective aspect)