program optimization vs American spelling

program optimization and American spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
program optimization	Yes	No	No	No
American spelling	Yes	No	No	No

program optimization (noun)	American spelling (noun)
the process of modifying a software system to make some aspect of it work more efficiently or use fewer resources.	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')