Outliers: Outliers are extreme data points that fall far from the other data values. They may or may not be influential; outliers that are also influential have a strong effect on the regression model.
Leverage: Leverage refers to how much an individual data point affects its own predicted value. Points with high leverage can potentially be influential if they deviate significantly from other observations.
Cook's Distance: Cook's Distance is a measure used to identify influential points in a regression model. It quantifies how much the estimated parameters would change if each observation were removed one at a time.