The main enemy throughout the Terminator Franchise has always been referred to as Skynet, the master of the machines and the seemingly omnipotent force that wiped half of the human race from existence when it instigated a thermonuclear war against strategic targets across the world; aka Judgment Day. In truth Skynet is nothing more than a network of US military assets capable of being controlled from one location. Skynet has always been controlled by humans, but the US Military's dream was for this system to be automated, yet obedient, in a bid to remove human error, hesitation, and corruption from strategic decisions.
In 1991's cult science fiction action thriller Terminator 2: Judgment Day it was explained that Miles Bennett Dyson, an engineer for Cyberdyne Systems was developing an artifcial intelligence capable of eventually controlling the Skynet Defense Network. Dyson's AI was a scaled up version of the Neural Network Processor he had been reverse engineering since it was discovered in a Cyberdyne Systems owned factory in 1984. Dyson's AI was a collection of processors arranged in a similar fashion to neural pathways in the human brain, all housed within a larger super-processor. After the destruction of all of his work, the Cyberdyne Systems office were he worked and his unfortunate death, Dyson's Neural Network Processor AI was gone.
In the 2003 sequel Terminator 3: Rise of the Machines the AI that would be used to control Skynet was a software program developed inhouse by Cyber Research Systems, the automated weapons division of the US Air Force. This AI was developed to operate Skynet, and through Skynet the drones and termination units developed at CRS from patents and intelectual properties previous held by Cyberdyne Systems. This software AI uploaded itself to the internet, determined mankinds fate and masquerading as a supervirus instigated a 'firesale' against global electronic and computerised systems forcing the USAF to bring Skynet online. Reconnecting with itself Skynet concluded the firesale attack by instigating Judgment Day, the date; July 24th, 2004.
Terminator Genisys, like the Sarah Connor Chronicles before it, tries to push back the date of Judgment Day even further while utilising a new, more topical technology as the AI that will control Skynet. This time around the AI, which is called Genisys (hence the movies name), is an application developed for the mobile communications market, which will presumably instigate Judgment Day in a similar fashion as in Terminator 3. You'll never look at Sirius the same way again.
