The Apple of Eden is the fictional First Civilization artifact central to Assassin’s Creed II.
In Assassin’s Creed lore, Apples of Eden are Pieces of Eden created by the First Civilization, also called the Isu. They can influence minds and project powerful effects, making them highly valuable to both the Assassin Brotherhood and the Templar Order.
Assassin’s Creed II connects Ezio’s Renaissance missions to the search for one of these artifacts. Its importance reaches beyond the immediate political conspiracies in Italy and links the historical narrative to the modern-day storyline involving Desmond Miles.
The series contains several other Pieces of Eden, including staffs, swords, and shrouds. That broader category can cause confusion: “Piece of Eden” is the general term, while the Apple of Eden is the specific artifact associated with this question.