Value

HSV stands for hue, saturation and value. The illustration holds hue and saturation fixed while increasing value from black to vivid blue.

At 0% value the result is black. At 100% value a saturated blue remains blue; increasing value does not necessarily make it white.

This is the key difference from HSL lightness. HSL reaches white at 100% lightness, whereas the result at 100% HSV value still depends on saturation and hue.