Taylor was a college acquaintance of Joseph Staten, and he recommended her as a possible voice for Cortana to audio director.
A fragment of Cortana carrying information gleaned from a Forerunner artifact combines with Cortana's main self on Pillar of Autumn before the ship escapes the planet, leading to the events of Combat Evolved.
During gameplay, Cortana provides backstory and tactical information to the player, who often assumes the role of Petty Officer John-117.
As an artificial construct, Cortana has no physical form or being.
The character's was performed by Mackenzie Mason.
Cortana helps direct human survivors scattered across the ring and assists the Master Chief in his missions.
Cortana makes a small appearance in 2010's , set shortly before the events of Combat Evolved.
In , a Covenant fleet arrives above Earth, and Cortana assists in the defense.