In the future the world is ruled by Skynet, a network of computers bent on eliminating mankind; Connor will soon become the mother of John Connor, the child who grows up to lead the humans in resistance against Skynet. As the story progresses, the human veneer of skin is progressively stripped from the Terminator, and the naked machinery is revealed.
Some aspects of the story were sufficiently similar to Harlan Ellison's short story Soldier that an acknowledgement of Ellison's story was placed in the credits. (Although to this wikipedian, the killer robot disguised as a human also drew heavily, and unacknowledged, on Philip K. Dick's short story Second Variety). A similar plot of a killer machine sent back in time to change history was seen in a fairly obscure film from 1966 entitled Cyborg 2087
A sequel, Terminator 2: Judgement Day was also directed by James Cameron, and again featured Arnold Schwarzenegger.