Contract for difference (CFD)

is a financial contract that pays the differences in the settlement price between the open and closing trades.

If the closing trade price is higher than the opening price, then the seller will pay the buyer the difference, and that will be the buyer’s profit.
The opposite is also true.
That is, if the current asset price is lower at the exit price than the value at the contract’s opening, then the seller, rather than the buyer, will benefit from the difference.

With this type of trade you have no ownership of the underlying assets.