production line vs assembly line

production line and assembly line both are nouns.

Word	Noun	Adjective	Verb	Adverb
production line	Yes	No	No	No
assembly line	Yes	No	No	No

As nouns, production line and assembly line are synonyms defined as:

production line and assembly line: mechanical system in a factory whereby an article is conveyed through sites at which successive operations are performed on it

Other synonyms of production line include line.

production line (noun)	assembly line (noun)
mechanical system in a factory whereby an article is conveyed through sites at which successive operations are performed on it	mechanical system in a factory whereby an article is conveyed through sites at which successive operations are performed on it