business line vs line of products

business line and line of products both are nouns.

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

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

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

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

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