Collage (From the French: coller, to glue), is a technique of an art production, primarily used in the visual arts, where the artwork is made from an assemblage of different forms, thus creating a new whole.
In her book SoulCollage® Evolving (pages 87; 4), Seena Frost explains that collage is the medium for SoulCollage® "because it quiets fears you may have about not having talent to make "art". Everyone can choose an image, cut it out, and glue it down.... Collage is a metaphor for any discovering, gathering and reweaving of energy bits already formed and present in the universe. A new and personal creation can be made from the ever-present divine chaos of images all around us. Just choose, assemble, name, and then inhabit your SoulCollage® cards".
Here are two other quotes which are favourites of mine in describing or explaining collage:
“Collage artists are as much editors and arrangers as they are creators.” Cecil Touchon (Collage Artist). Masters: Collage: Major Works by Leading Artists. Lark Books. 2010. p. 86
“Originality doesn’t mean making something that’s completely new; nothing is completely new. Originality means bending and shaping what’s come before until it belongs to you.” ~ Robert Hunt (Collage Artist). Masters: Collage: Major Works by Leading Artists. Lark Books. 2010. p. 59
Collage also has an interesting history as this Wikipedia article reveals.