Bimodal distribution

A bimodal shape has two clear humps, which often signals that the data mix two different groups. For example, heights measured from a room of both children and adults may peak once near each group's typical height. Each peak is a mode, so two peaks means two modes, in contrast to a single-peaked (unimodal) distribution. When you see two modes, it is worth asking whether the data should be split into subgroups.