It might feel like there is going on within a collage, and you are right, there is! There could be multiple reference points to look at and they could consist of used material meant for another purpose, but it is created into an assortment of graphic elements. It was first used with found material from newspaper, fabric, and more. Then, it was developed into collaging photographic images which is called a photomontage and has been around since the 1920s. Collage takes a lot of more thought than people think. Designers have to think about the type of medium that should be used and how they should coexist with one another. After that, they have to know how to be composited into a complete piece. Anything that can be related to a graphic element will help direct the message in the way you need it as well.