bits per inch vs bpi

bits per inch and bpi both are nouns.

Word	Noun	Adjective	Verb	Adverb
bits per inch	Yes	No	No	No
bpi	Yes	No	No	No

As nouns, bits per inch and bpi are synonyms defined as:

bits per inch and bpi: a measure of how densely information is packed on a storage medium

bits per inch (noun)	bpi (noun)
a measure of how densely information is packed on a storage medium	a measure of how densely information is packed on a storage medium