Source: Image of graph and table created by Ryan Backman
A point that is so large or small as to be unusual, given the rest of the data points.
If a point is larger than Q3 + 1.5xIQR, or smaller than Q1 - 1.5xIQR, then it is an outlier.
A graphical display showing a modified version of the five number summary. If a distribution has outliers, then the "whiskers" only extend to the highest and lowest points that are not outliers.