Terminator 2: Judgement Day is set in 1995 Los Angeles, two years before Judgement Day, the eponymous nuclear holocaust which will result in the near-extinction of humanity and the rise of an evil Artificial Intelligence called Skynet.
The film follows John Connor, who is living with foster parents while his mother Sarah Connor (who was the main character in the first film) is in a mental asylum after getting caught trying to blow up a robotics factory in an effort to stop - or at least postpone - Judgement Day.
Because John will eventually unite humanity and fight against the machines, Skynet wants him dead. To that end, they send back a T-1000 Terminator back to kill him. Realizing there was a threat to his life, though, future John sent back another Terminator to protect himself.
John and the friendly Terminator initially fight against the evil T-1000 alone, but they break Sarah out of her asylum. Now with Sarah, they fight against the T-1000 and ultimately win.
Meanwhile, the gang works to stop Judgement Day. They meet up with inventor Miles Dyson and after kidnapping him, convince him that any future technology should be destroyed. He helps them do this and they ultimately postpone Judgement Day.
