line of products vs line of merchandise

line of products and line of merchandise both are nouns.

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

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

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

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

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