The modern-day machine that reveals ancestral memories in Assassin's Creed is called the Animus.
The Animus allows a person to relive genetic memories inherited from ancestors. In the series, modern users enter the device while a computer reconstructs historical experiences, creating the playable settings of the past. The machine is the narrative link between contemporary characters and historical protagonists such as Altaïr, Ezio, and Connor.
The Animus does not literally send someone through time. Instead, it interprets genetic information and presents a simulated reconstruction of ancestral memories. The games use this explanation to combine a modern science-fiction plot with historical action-adventure gameplay.
The Helix is a later entertainment and research system associated with Abstergo, while the Bleeding Effect is a condition in which skills or memories from repeated Animus sessions affect the user. The Observatory is an important location in Black Flag, not a memory machine. These terms belong to the same fictional universe but have different functions.