assembly program vs assembler

assembly program and assembler both are nouns.

Word	Noun	Adjective	Verb	Adverb
assembly program	Yes	No	No	No
assembler	Yes	No	No	No

As nouns, assembly program and assembler are synonyms defined as:

assembly program and assembler: a program to convert assembly language into machine language

assembly program (noun)	assembler (noun)
a program to convert assembly language into machine language	a program to convert assembly language into machine language