The fitting of a straight Line through a given set of points according to some specified goodness-of-fit criterion. The most common form of linear regression is Least Squares Fitting.
See also Least Squares Fitting, Multiple Regression, Nonlinear Least Squares Fitting
References
Edwards, A. L. An Introduction to Linear Regression and Correlation. San Francisco, CA: W. H. Freeman, 1976.
Edwards, A. L. Multiple Regression and the Analysis of Variance and Covariance. San Francisco, CA: W. H. Freeman, 1979.