How do musical modes differ from major and minor scales?

In music theory, the distinction between modes and major/minor scales is largely historical and functional, as major and minor scales are themselves specific types of modes.1

A mode is a theoretical framework that defines how notes are ordered within a scale to create a melody, specifying which notes are used and their relative importance, such as the final note and the dominant. Historically, Western music relied on a system of church modes, which were later expanded by theorists like Henricus Glareanus to include the Ionian and Aeolian modes—which are identical to the modern major and natural minor scales, respectively.21

The primary differences are:

• Systemic Scope: While "mode" is a broad term for any ordering of scale notes, the major-minor system refers to a specific dual-tonality framework that dominated Western music from the 18th century onward.1
• Chromaticism: Modern major and minor scales are often subject to chromatic alterations—such as the raised seventh in harmonic or melodic minor scales—to satisfy the requirements of diatonic harmony.2
• Terminology: Music that utilizes the older, non-major/minor modal patterns is often specifically labeled as "modal" to distinguish it from the standard tonal system.1