In Terminator, Skynet is an advanced computer system equipped with artificial intelligence. Once it became self-aware, it perceived humanity as a threat to its existence due to the scientists' attempts at Cyberdyne Systems to deactivate it after it had gained self-awareness. As a result, Skynet chose to unleash the nuclear holocaust known as Judgment Day. Later, it waged war against humanity by developing and deploying an army of hunter-killers and terminators. The survivors formed a group called "the Resistance" under the leadership of John Connor.