social organisation vs social organization

social organisation and social organization both are nouns.

Word	Noun	Adjective	Verb	Adverb
social organisation	Yes	No	No	No
social organization	Yes	No	No	No

As nouns, social organisation and social organization are synonyms defined as:

social organisation and social organization: the people in a society considered as a system organized by a characteristic pattern of relationships

Other synonyms of social organisation include social structure, social system, structure.

social organisation (noun)	social organization (noun)
the people in a society considered as a system organized by a characteristic pattern of relationships	the people in a society considered as a system organized by a characteristic pattern of relationships