The Animus is the memory-simulation machine in Assassin’s Creed.
Within the series, the device allows a person to access genetic memories inherited from ancestors. Users lie inside the machine while it reconstructs past experiences, creating the playable historical sequences that define the games.
The Animus is developed and used by Abstergo Industries, the modern organization associated with the Templars. The Assassin Brotherhood and its allies later use modified versions of the technology. Desmond Miles is the best-known early user, experiencing the memories of Altaïr, Ezio, and other ancestors.
The device does not function as ordinary time travel. The games present its experiences as reconstructions of inherited memories, which explains why modern characters can observe and interact with historical events without physically traveling to the past. The Helix is a later entertainment-oriented system, while Eagle Vision is an enhanced perception ability rather than a machine.