The Animus is the fictional device used to explore ancestral memories in Assassin's Creed's modern-day story.
Users enter the machine and experience genetic memories inherited from an ancestor. This framing device allows the games to move between a contemporary storyline and historical adventures without treating the player as literally traveling through time.
The Animus is central to the early games, in which subjects are connected to the machine by Abstergo or by the modern Assassin organization. Repeated exposure can produce the Bleeding Effect, a fictional phenomenon in which learned skills and memories affect the user.
The Apple of Eden is a powerful Isu artifact, not the memory machine. Eagle Vision is an Assassin ability, while the Bleeding Effect describes a consequence of Animus use. These terms are connected to the device but are not alternate names for it.