Why do water drip on the back side of engine on a 2002 Chevy silvarado 2500 HD 4x4?

Is it WATER or Antifreeze ? If it's WATER then it is coming out of the A/C box. It is condensation and that is normal.

If it's antifreeze Then it is coming from the engine and I need to know what engine you have to help on that part.