A gradient is a graduated blend between two or more colors or between two tints of the same color. The output device you use affects how gradients color-separate.
Gradients can include Paper, process colors, spot colors, or mixed ink colors using any color mode. Gradients are defined by a series of color stops in the gradient bar. A stop is the point at which a gradient changes from one color to the next, and is identified by a color square under the gradient bar. By default, a gradient starts with two colors and a midpoint at 50%.