A boxplot (or box-and-whisker plot) summarizes the distribution of a continuous variable by showing its median, quartiles, and potential outliers. The box represents the interquartile range (IQR), the line inside shows the median, and whiskers indicate variability outside the upper and lower quartiles.
Boxplots are excellent for comparing distributions across groups. For example, they can show exam scores across several school classes, helping identify which classes have more variability or skewed performance.
They’re commonly used in data science, quality control, and reporting to detect outliers, assess symmetry, and compare groups. Because they show five-number summaries in a compact space, they’re ideal for side-by-side comparisons.