Enharmonic equivalence

In music, two written notes have enharmonic equivalence if they produce the same pitch but are notated differently. The enharmonic relation extends to pitch classes, intervals, chords, and key signatures. The term derives from Latin enharmonicus, in turn from Late Latin enarmonius, from Ancient Greek ἐναρμόνιος (enarmónios), from ἐν ('in') and ἁρμονία ('harmony').