line of products vs line of business

line of products and line of business both are nouns.

Word	Noun	Adjective	Verb	Adverb
line of products	Yes	No	No	No
line of business	Yes	No	No	No

As nouns, line of products and line of business are synonyms defined as:

line of products and line of business: a particular kind of product or merchandise

Other synonyms of line of products include business line, line, line of merchandise, product line.

line of products (noun)	line of business (noun)
a particular kind of product or merchandise	a particular kind of commercial enterprise
	a particular kind of product or merchandise