Collage
A technique of combining diverse, often unrelated visual fragments into one new, unified composition.
In practice
Collage combines fragments from different sources, such as photos, paper, type, fabric or found printed matter, into a new composition with its own meaning. The joins and mismatches between pieces are often part of the effect. An album cover made from cut magazine photos, ticket stubs and torn colored paper is a collage, and so is a digital poster assembled from scanned textures and photographs.
Often confused with photomontage
Collage combines fragments of any material into one composition; photomontage is the narrower case built specifically from photographs.
Try this
Cut ten fragments from old magazines and arrange them into an image that none of them shows alone.