decolonisation vs decolonization

decolonisation and decolonization both are nouns.

Word	Noun	Adjective	Verb	Adverb
decolonisation	Yes	No	No	No
decolonization	Yes	No	No	No

As nouns, decolonisation and decolonization are synonyms defined as:

decolonisation and decolonization: the action of changing from colonial to independent status

decolonisation (noun)	decolonization (noun)
the action of changing from colonial to independent status	the action of changing from colonial to independent status