Total casualties. Even civilian "collateral damage" casualties are like an order of magnitude lower than they were in WW2. Bombing raids used to kill tens of thousands of civilians in a single night. Bombs were so inaccurate the only way to ensure you hit the target was to employ them en masse.
Now, we can hit a single building with a handful of guided bombs or cruise missiles and civilian losses are typically in the double digits.
Now, we can hit a single building with a handful of guided bombs or cruise missiles and civilian losses are typically in the double digits.