Black and White
Black and white are two colours. Like all colours, they are created by the way light is reflected by an object. With white it is a lot of light, with black no light or almost no light.
We think mainly of drawings, photos and films that are black and white. So you don't see any colours like green, red or blue in them. Drawings were made only with black, with white, or with mixtures of both, which are shades of grey.
In the past, it was often difficult to find colours for painting and drawing. They were usually expensive. It was much cheaper and easier to draw something with a single pencil. When photographs and films could be made, colours could not yet be reproduced well. Before 1930, all films were black and white. It was not until the 1950s and 1960s that they were replaced by colour films. In 1967, you could watch television in colour for the first time in Germany.
Sometimes people still take photos and make films in black and white. Some people find this particularly beautiful: you can see the differences, the contrasts. Such photos and films have a different effect, for example sad or distinguished. That's why many photo artists take black-and-white photos.
After all, black and white is also said in another sense. Sometimes a person thinks very simply. He sees only the good or only the bad in something. He is then accused of thinking in black and white.