Modes

Modes is a term used across disciplines to denote distinct states, patterns, or ways of functioning within a system. In general, a mode is a specified condition or configuration that defines permissible actions or behaviors.

In statistics and data analysis, the mode is the value that appears most frequently in a dataset. A dataset can have a single mode (unimodal), more than one mode (multimodal), or no mode if all values are equally frequent. The mode is different from the mean and median and can be sensitive to data grouping.

In music, a mode refers to a type of scale or melodic framework. Medieval church modes (Dorian, Phrygian, Lydian, Mixolydian) contrasted with the Ionian and Aeolian that correspond to major and natural minor scales. Modern music also uses modal harmony where the scale, rather than the tonic key, guides melodic and harmonic content.

In physics and engineering, a mode is a specific pattern of motion that a system can sustain, such as a standing wave in a string or a vibrational shape in a solid. Each mode has a natural frequency; exciting a system at that frequency produces resonance.

In computing and technology, modes describe different operating states or user interaction states, such as manual vs. automatic mode, power modes (on, off, sleep), or display modes.

In other contexts, the term is used in transport (mode of transport), communication (input/output modes), and more generally to denote the prevailing condition or configuration of a system.