The film follows Sarah Connor and her ten-year-old son John as they are pursued by a new, more advanced Terminator: the liquid metal, shapeshifting T-1000, sent back in time to kill John Connor and prevent him from becoming the leader of the human resistance. A second, less advanced Terminator is also sent back in time to protect John. It is the sequel to the 1984 film The Terminator, as well as the second installment in the Terminator franchise.

References:
https://en.wikipedia.org/wiki/Terminator_2:_Judgment_Day