DefinitionA linear regression line is a ‘line of best fit’ for the data in the sense that it minimizes the sum of the squares of the vertical distances of the points from the line. Least squares regression is a statistical technique that is used to determine the “best” linear relationship between one dependent variable and one or more independent variables by minimizing the sum of the squares of the differences between the observed and predicted values. For example for a dataset {xi,yi} then the least squares regression line y=mx+b will minimize the sum of squares ∑(yi−mxi+b)2 and it provides the best linear fit.