mid-14c., from Old French difference (12c.) "difference, distinction; argument, dispute," from Latin differentia "diversity, difference," from differentem (nominative differens), present participle of differre "to set apart" (see differ). Sense of "a quarrel" first attested late 14c. Colloquial phrase what's the diff? first recorded 1896.[difference etymology, difference origin, 英语词源]