Contract for Difference, commonly just called CFD, is a derivative for trading stocks and also commodities. It is a margin product which makes it possible to get a gearing effect similar as buying stocks on margin. It can be used for long and short trades.
CFDs have been available in the institutional market since the early 1990s. They were introduced to the retail market around 1996. CFDs are available to trade the stocks on most Western stockmarkets including pretty much all of Europe and of the US.