That's not really correct either. Regression is but a small (and useful) part of statistics -- it's the part of statistics that most engineers use, but statisti

That's not really correct either. Regression is but a small (and useful) part of statistics -- it's the part of statistics that most engineers use, but statistics goes beyond regression. For instance, sampling theory is not regression. Hypothesis testing is not regression. Causal inference is not regression. Probability undergirds a lot of statistical methods.