The T1000 used a whole new level of technology; nano-technology. The T1000 was not just a machine, it was a combination of millions and millions of microscopic machines network linked together in a cohesion subroutine. Each machine was constructed of mimetic poly-alloy, a pseudo-living creature composed not of living cells, but rather billions of tiny machines. The T1000 could change shape simply by ordering parts of itself to move into a new position. The T1000 could imitate perfectly anything that it sampled by physical contact, including perfect copies of humans, though complex machines were beyond the limit of the copying process. It could quickly reproduce simple machines; prybars, wedges, blades, but it could not reproduce complex machines such as firearms and other projectile or energy weapons as these had complex moving parts and required other chemicals and/or special fuels. Powered by an advanced molecular power source superior to that of even the T800, the T1000 could physically match the machine strength of any lesser machine.
A molecular matrix brain allowed the T1000 to carry the same data, programs, and detailed files that the T800 series could, as well as actually be able to learn. The T1000 also differed from the T800 in that it had only one mode; autonomous. When SKYNET created the T1000, it was desperate for victory, but it also realized that it was, quite possibly, creating the one weapon that might turn against its own creator. A weapon that SKYNET didn't know if it could defend itself against. The nature and disposition of the T1000 was hard to calculate and SKYNET took great pains into programming the unit with a myriad of fail-safes to keep it from turning on the creator. Still, SKYNET was unsure about the wisdom of creating such a powerful unit with total autonomy and free will.
