SD(X): SD(X), also known as the standard deviation of X, is simply the square root of Var(X). It measures how much individual data points vary from the mean.
Covariance: Covariance is a measure that describes how two random variables vary together. It indicates whether they move in similar or opposite directions.
Correlation Coefficient: The correlation coefficient quantifies the strength and directionality of the linear relationship between two variables. It ranges from -1 to 1, where -1 indicates a perfect negative correlation, 0 indicates no correlation, and 1 indicates a perfect positive correlation.