The coefficient of determination. The percentage of variation in the dependent variable that is explained by the regression equation.
Square of the correlation coefficient. The proportion of the variability in one series that can be explained by the variability of one or more other series in context of regression. It represents a measure of the quality of fit. 100% R-square means perfect predictability.
Square of the correlation coefficient proportion of the variability explained by the linear regression model. For example, an r squared of 75% means that 75% of the variability observed in the dependent variable is explained by the independent variable.