The virtual-reality machine in the Assassin's Creed series is called the Animus.
The Animus allows a user to relive genetic memories inherited from ancestors. In the games, this device provides the framework for exploring historical settings while the user's present-day body remains connected to the machine.
The Animus is not presented as ordinary time travel. Its fictional technology reads ancestral memories encoded through DNA, letting modern subjects experience the lives of people such as Altaïr, Ezio, Edward Kenway, and Bayek. The device also lets Abstergo Industries study historical memories for its own goals.
The Helix is a separate entertainment and research interface associated with Abstergo, while the Bleeding Effect describes a side effect of prolonged Animus exposure. These related terms are often mixed up, but only the Animus is the machine itself.