The virtual-memory device in Assassin's Creed is called the Animus.
The Animus lets a modern user relive genetic memories inherited from an ancestor. In the original game, Desmond Miles uses it to experience Altaïr Ibn-La'Ahad's life during the Third Crusade.
The device provides the narrative link between historical settings and the modern-day storyline. It also explains why the player can explore different eras while controlling characters from a single fictional universe.
The Helix is another Abstergo memory-experience system introduced later in the series, so it is a plausible mix-up. Eagle Vision is an ability rather than a machine, and an Apple of Eden is a Piece of Eden with different powers.