In Assassin's Creed lore, the Animus lets users experience ancestral genetic memories.
The Animus is a fictional device developed by Abstergo Industries, the modern organization controlled by the Templars. It uses a person’s genetic material to access memories inherited from ancestors, allowing the user to relive historical events without physically traveling into the past.
Desmond Miles is the first major character shown using the machine. In the original Assassin’s Creed, Abstergo forces him to relive Altaïr’s memories. Later games show different Animus models, portable systems and simulation technology used by both Abstergo and the Assassin Brotherhood.
The series treats the Animus as a storytelling bridge between historical gameplay and a modern conspiracy plot. It is not the same as an Isu artifact such as the Apple of Eden. The Helix, meanwhile, is a later Abstergo entertainment platform based on Animus technology rather than the name of the original machine.