high relief vs alto relievo

high relief and alto relievo both are nouns.

Word	Noun	Adjective	Verb	Adverb
high relief	Yes	No	No	No
alto relievo	Yes	No	No	No

As nouns, high relief and alto relievo are synonyms defined as:

high relief and alto relievo: a sculptural relief in which forms extend out from the background to at least half their depth

Other synonyms of high relief include alto rilievo.

high relief (noun)	alto relievo (noun)
a sculptural relief in which forms extend out from the background to at least half their depth	a sculptural relief in which forms extend out from the background to at least half their depth