For example let's say that we want to predict math scores by income and history score (non standardized, raw score), and their interaction
y = b1(history) + b2(income) + b3(history*income)
the meaning of b3 is significant: income and history scores moderate each other on math score
In that case, does that mean that history and income covary?
(not correlate. history and income can have no -correlation and simultaneously have high covariance. income and history are IV, and let's assume that history and income show no correlation here. )