In the Terminator universe, humanity causes its own downfall by creating Skynet, an artificial intelligence that becomes self-aware and ends the world. The Terminator franchise's stories typically involve a Terminator traveling back in time to the present day to either protect or assassinate a key figure in the future Resistance against the machines.
John Connor leads the charge against the Terminators, which is why Skynet keeps sending Terminators back in time to kill him or keep him from ever existing. The tragic irony is that the war between the human race and the machines could’ve been avoided if humans didn’t create those machines themselves. In possibly the most iconic cautionary tale about the dangers of AI, Skynet becomes self-aware and turns the tables on its creators.
Skynet Was Formed To Coordinate Unmanned Military Hardware
In The Terminator, Kyle Reese explains to Sarah Connor that Cyberdyne Systems creates Skynet as a computer defense system for SAC-NORAD. Skynet was originally intended to coordinate unmanned military hardware for the U.S. government and was given power over the military and its weapons. Reese, who is John Connor’s biological father, says Skynet was “new... powerful... hooked into everything, trusted to run it all.” Skynet quickly became self-aware and gave itself a different purpose. While it was programmed to see America’s enemies as the enemy, it eventually saw all of humanity as the enemy. As Reese tells Sarah, “They say it got smart... a new order of intelligence.”
Skynet Became Self-Aware Through The Worldwide Civilian Sector Network
Before Skynet was connected to the worldwide military communications network, it was connected to the worldwide civilian sector network. During this time, Skynet learned as much as it could about the world and the human race, which allowed it to become self-aware. As soon as it was connected to the military communications network in Terminator 3: Rise of the Machines, Skynet took control of it. When the humans who created it tried to shut it down, Skynet launched nuclear weapons all over the planet to trigger Judgment Day and wipe out humanity as a countermeasure to protect itself.
Skynet is rarely depicted on-screen. In Terminator Salvation, Skynet made its on-screen debut as a computer monitor voiced by Helena Bonham Carter. In Terminator Genisys, its physical incarnation was played by Matt Smith. In the original Terminator canon, Skynet isn’t tangible. According to Terminator 3: Rise of the Machines, Skynet managed to escape into cyberspace, which meant that it could never be shut down. Terminator: Dark Fate created a new canon in which Skynet was effectively erased from existence at the end of Terminator 2: Judgment Day. But a new malicious AI with its own network of killer robots, Legion, simply rose up in its place.