I noticed that people often mingle  Monochrome photos with Black & White photos. But they are not similar indeed. Monochrome photos are photos that contain variations of only one color and nothing else. This could be different shades of blue, green, or grey, for example. Black and white photography contains variants of the color grey ranging from absolute black to absolute white. This means that, by definition, all black and white photos are monochrome photos, but not the other way around.