Decoupage is the creative art of assembling and composing paper cut outs on objects for decoration. The word 'decoupage' comes from the French word 'decouper' meaning 'to cut out'. Decoupage is thought to have its origins in 17th century Italy, where paper cut outs were placed on painted backgrounds as an inexpensive alternative to hand painted furniture.
Commonly, with decoupage, an object like a small box or an item of furniture is covered by cut outs from magazines or from purpose manufactured papers. Each layer is sealed with multiple layers of varnish until the stuck-on appearance disappears and the result looks like painting or inlay work.
Here are a few great examples of decoupage work that I found available on Etsy.