The mode is the value that appears most frequently in a dataset.
A dataset can have one mode (unimodal), more than one mode (multimodal), or no mode (if all values appear equally often). The mode is the only measure of central tendency that can be used with categorical data. Unlike the mean and median, the mode is not affected by extreme values. Mode is used in market research, inventory management, and analyzing categorical survey data.
The concept of mode as a statistical measure was developed in the 19th century alongside other measures of central tendency. The term "mode" was introduced by Karl Pearson in 1895. Mode analysis became important in the 20th century for quality control, manufacturing, and social science research where identifying the most common category is valuable.