The Animus is the fictional machine that lets subjects experience ancestral memories in Assassin's Creed.
In the series, the Animus reads genetic memories inherited through a person's ancestry. A modern subject enters the machine while software reconstructs historical experiences as an interactive simulation. This device allows the games to move between a contemporary storyline and different historical periods.
The Animus is not the same as Eagle Vision, which is a perception ability used by Assassins and other characters. The Apple of Eden is a powerful Isu artifact, while Helix is the name of a later entertainment and research platform associated with Abstergo.
Desmond Miles is the best-known early Animus subject. Later stories feature several unnamed or differently identified users. Although the machine is fictional, its narrative purpose is consistent throughout the franchise: it connects modern characters to the lives and skills of their ancestors.