Photoshop and many other computer programs allow you to select a colour by adjusting HSB sliders. In most cases, the sliders work like the sliders in the illustration—they’re connected in a simple way to the RGB values of the pixels displayed. They aren’t closely linked to the perceptual qualities of saturation and luminance.
The S(saturation) slider changes the luminance as well as the saturation.
The B(brightness) slider goes down to pure black, but it doesn’t go up to pure white unless the S slider is set at zero.