This model is somewhat analogous to Munsell's system of hue, value, and chroma in that it uses three similar axes to define a color. Hue defines the color itself, for example, red in distinction to blue or yellow. In this respect, HLS is very similar to Munsell's color wheel. Although Munsell used a different method for indicating hue, both arrange the colors in a circular pattern and progress them through compass points.
Saturation indicates the degree to which the hue differs from a neutral gray.
This is similar to Munsell's chroma. Lightness indicates the level of illumination. In this respect, the lightness axis is similar to Munsell's value axis. By specifying the hue degree and saturation percentage and using the slider bar to control the lightness, you can create any of millions of colors. The values, regardless of what they're called, are very similar.