How does a contract for difference work?

Hello Moses,
Experienced traders mainly use a contract for differences, as it is an advanced strategy. CDF is a setting whereby the differences in agreement between opening and closing trade prices are settled by cash.
It requires the seller to pay the buyer the difference in the present-day worth of an asset and its price during the time of the contract.
Here, you are not supposed to buy nor sell the commodity; however, you should barter in the number of units in that commodity according to whether you speculate that the prices will rise or fall. 
CFD instruments may include, amongst others, shares and stock indices. If the cost of a tool favors you, then you get the amount of CFD units that you have bought or sold. If the price of the instrument does not pick you, then you will be making a loss.