It's not Terminator... The Terminator series ended with Terminator 1&2... Those two were classics of the "invincible killing machine chasing hero/heroine through America" genre.
Terminator 3 tried to copy that genre, kinda failed, could not be compared to the first two.
Then Terminator 4 would probably be totally different from the first two, and would have nothing to do with them except the name, and oh yes, continuation.