social function vs social occasion

social function and social occasion both are nouns.

Word	Noun	Adjective	Verb	Adverb
social function	Yes	No	No	No
social occasion	Yes	No	No	No

As nouns, social function and social occasion are synonyms defined as:

social function and social occasion: a formal or official social gathering or ceremony of people

Other synonyms of social function include affair, function, occasion, social affair, social gathering.

social function (noun)	social occasion (noun)
a formal or official social gathering or ceremony of people	a formal or official social gathering or ceremony of people