best fit
the theoretical pattern that best accounts for the relationships among variables in a data set. For example, a regression equation having the best fit to sample data is the one that minimizes differences between observed and predicted values. On a scatterplot, a line of best fit provides a visual depiction of this pattern, allowing extrapolation to values not part of the original data set. It is important to note that the best-fitting pattern is not necessarily the one that generated the observed data, as other patterns not considered may provide a superior fit.