high bar vs horizontal bar

high bar and horizontal bar both are nouns.

Word	Noun	Adjective	Verb	Adverb
high bar	Yes	No	No	No
horizontal bar	Yes	No	No	No

As nouns, high bar and horizontal bar are synonyms defined as:

high bar and horizontal bar: gymnastic apparatus consisting of a bar supported in a horizontal position by uprights at both ends

high bar (noun)	horizontal bar (noun)
gymnastic apparatus consisting of a bar supported in a horizontal position by uprights at both ends	gymnastic apparatus consisting of a bar supported in a horizontal position by uprights at both ends