R-squared is a statistical measure that indicates how well a model explains the variability of a dataset. It ranges from 0 to 1, where 0 means the model does not explain any variability, and 1 means it explains all variability. A higher R-squared value suggests a better fit of the model to the data. In regression analysis, R-squared helps assess the effectiveness of the independent variables in predicting the dependent variable. However, it is important to note that a high R-squared does not always imply causation, and it should be used alongside other metrics for a comprehensive evaluation.