Just because you discover a relationship does not mean that one variable caused the other.
Regression is also a form of prediction.
In linear regression, a line of best fit is computed for a given set of paired scores. Finally, scatterplots help you visualize the relationships between bivariate and multivariate data. So far, we have been looking at distributions involving a single variable, univariate distributions. Now we look at cases where two measurements are made from each subject. Of interest is whether or not those two variables show any relationship to each other.