Black is a color with several subtle differences in meaning.
Color or light:
Black can be defined as the visual impression experienced in directions
from which no visible light reaches the eye. (This makes a contrast with
whiteness, the impression of any combination of colors of light that equally
stimulates all three types of color-sensitive visual receptors.)
Pigments that absorb light rather than reflect it back to the eye "look black". A black pigment can, however, result from a combination of several pigments that collectively absorb all colors. If appropriate proportions of three primary pigments are mixed, the result reflects so little light as to be called "black".
This provides two superficially opposite but actually complementary descriptions of black. Black is the lack of all colors of light, or an exhaustive combination of multiple colors of pigment.
Human:
The term black is often used in the West to denote race for persons whose
skin color ranges from light to dark shades of brown. For a discussion
of usage, see the main entry at Blacks.
Read more about "Usage and Symbolism" of Black Color.