>>212801609 (OP)The Oracle is a program. She was created to understand Human psychology. She came up with the system of the One, which stabilized the Matrix through periodic reboots and the introduction of Choice.
However over the centuries of reboots, the Oracle grew fond of Humanity. She devised a plan to bring peace between Humans and Machines and break the cycle, which involved
a. Corrupting Smith (to give Neo his bargaining chip) and
b. Making sure Neo (the One) picked the door he wasn't supposed to pick.
Next step was choosing a suitable One candidate. She picked Neo because he fit the psychological profile of someone reckless who would choose the other door.
Then she activated the One programming in Neo, by giving him the cookie at the end of their first meeting. We are told over and over that certain foods can modify code in the Matrix (just as the Merovingian shows with the cake).
The cookie both activated the One programming in Neo, and also embedded a virus on his code so that he would make Smith go rogue. When Neo died at the end of the movie his One programming kicked in. When he attacked Smith, he also infected him.
tl;dr - Get better at interpreting movies brainlet