Desmond Miles is the Animus operator and modern-day protagonist of the early Assassin's Creed games.
Desmond is an Assassin descendant abducted by Abstergo Industries and forced to use the Animus, a machine that allows him to experience genetic memories inherited from his ancestors. Through those sessions, he relives the lives of Altaïr Ibn-La'Ahad, Ezio Auditore, and Connor Kenway.
His modern-day storyline connects the historical episodes and reveals the continuing struggle between the Assassin Brotherhood and the Templars. Desmond is not the historical protagonist of those sequences; he is the person experiencing them in the present day.
William Miles is Desmond's father and an important Assassin leader, while Rebecca Crane is a technical specialist who supports the team. Clay Kaczmarek is another Animus subject associated with Abstergo, making all three names possible sources of confusion.