What is T-101?
A huge mistake made by the writers of Terminator 3: Rise of the Machines. In the movie, Arnold's character refers to the previous Terminator from Terminator 2 as "a different T-101" when in fact the actual designation of it is T-800 Model 101.
Arnold's character in T3 is a T-850 because the 800 series has only one compact nuclear power cell, while the 850 series has two hydrogen fuel cell power sources, among other differences.
T-850: "That was a different T-101."
Arnold (Ahnuld) Schwarzenegger's alter ego in the Terminator movies.
While not the most advanced, the T-101 is the most powerful Terminator ever built by far, able to destroy a
T-101: "Stay here. I'll be back."
*many years later*
John Connor: "Don't you remember anything?"
T-101: "That was a different T-101."