CFD= Contracts For Difference. It works also with leverage.
You can agree: buy 100 shares NII for $6.75. Then the price gets &7.00.
The differences is $0.25 a share. This is your profit x 100.
But also the reverse.
If the leverage is 1:100. Then you pay for 100 shares CFD's 100x 6.75x1/10= $67.50.
You can with less money so invest (beter talk of speculate) on stocks to make quick profit