Black
In light, black is the absence of all color. It is a shade. In painting, however, black pigment is the combination of all colors. In heraldry, black is called "sable". It is the opposite of white. No color can have the same level of dark pigmentation without turning itself into black. It appears as a dark shade, that can reflect light into the rainbow.
Black in science and related
In science, an object that is fully black would absorb all the light that hits it. Because this object would not reflect any light, the human eye would not see any colors coming from that object, and would see this object as black.
A way to create black objects is to mix is a pigments. A pigment works by reflecting only the color of other colored objects because they absorb more light.
Meaning of black
Black is associated with power, elegance, formality, safety, birth, male, evil and mystery. Black is the darkest color there is. Black, along with gray and white, is a nice neutral color. This means that it is not a hot color or a cool color.
Black is a color seen with fear and the unknown. It can have a bad meaning (blackbird, black bunny) or a good meaning ('in the black', 'black is beautiful'). Black can stand for strength and power. It can be a formal, elegant and high-class color (black tie, black Mercedes).