As the original image is converted to pixels in the digital camera, then to dots on your monitor, colors can change and shift. Knowing how to manage color for an accurate representation of the original image is critical for getting the best results. The saturation of color is a measurement of its purity or how much it has been diluted by white. Brightness refers to the amount of light the color reflects, or how much black is in the color.
Contrast is a measure of the rate of change of brightness in an image.
Very high contrast, for example, indicates both dark black and bright white content within the picture.