variation

The act, fact, or process of varying.

The extent or degree to which something varies.

Something different from another of the same type: synonym: difference.

Magnetic declination.

The existence within a species or other group of organisms of differences in form, function, or behavior, especially when hereditary.

A function that relates the values of one variable to those of other variables.

A form that is an altered version of a given theme, diverging from it by melodic ornamentation and by changes in harmony, rhythm, or key.

One of a series of forms based on a single theme.