colonization vs colonisation

colonization and colonisation both are nouns.

Word	Noun	Adjective	Verb	Adverb
colonization	Yes	No	No	No
colonisation	Yes	No	No	No

As nouns, colonization and colonisation are synonyms defined as:

colonization and colonisation: the act of colonizing; the establishment of colonies

Other synonyms of colonization include settlement.

colonization (noun)	colonisation (noun)
the act of colonizing; the establishment of colonies	the act of colonizing; the establishment of colonies