A multiple exposure is a technique wherein two or more  images are photographed, one on top of another

A multiple exposure photography  is a technique wherein two images are photographed, one on top of another. Back in the days when film was used, this technique was done by taking one photograph, then leaving the film in the same place and taking another photograph on top of it, before moving on to the next frame. If you take or edit a multiple exposure photograph in Black and White, you get better results. Why so? Because you wouldn’t have to think in-depth about color theory and the like.