demonetisation vs demonetization

demonetisation and demonetization both are nouns.

Word	Noun	Adjective	Verb	Adverb
demonetisation	Yes	No	No	No
demonetization	Yes	No	No	No

As nouns, demonetisation and demonetization are synonyms defined as:

demonetisation and demonetization: ending something (e.g. gold or silver) as no longer the legal tender of a country

demonetisation (noun)	demonetization (noun)
ending something (e.g. gold or silver) as no longer the legal tender of a country	ending something (e.g. gold or silver) as no longer the legal tender of a country