Posted by: Terror Q
Okay, first of all, please don't flame with: That's a stupid question! I'm asking, so for me it's a valuable one.
Well, in the Fall of Reach, I remembered that Cortana was a human construct, and for me that's the logical answer, but in Origins I and II, she knew a hell-of-a-lot about Forerunners. Anyone knows if she knew it because of her journey with 117, and getting information from perhaps the Halo control center, or is she a Forerunner AI? I remember Halsey said something like that in Halo: Reach, although I could be wrong.
Please, answer.
TL;DR: Check title.
She's not a forerunner, but since she's an AI and was gathering information from the Halos (constructed by the Forerunners) she probably got a lot of information from those installations. Assuming the Forerunners put the history of their race in the Halo databanks, she probably copied all of the information from the installations and learned about them that way. Probably the main reason why we saw her start to become corrupted in Halo 3, because AI's start to become rampant after absorbing too much information and can't keep their sub-routines in check.