Mode

The mode is the value that appears most often in a dataset — the most common outcome. Unlike the mean and median, it can be used even for categorical data, where it simply names the most frequent category.

The mode answers “what is typical in the sense of most popular,” which is exactly what you want for questions like the best-selling shoe size or the most common error code. A dataset can have no clear mode, or several (called bimodal or multimodal), and a second peak is often a clue that two different groups are mixed together in the data.