Your profit or loss (PnL) on a CFD position depends on how far the price moved, your volume, and the contract size:
PnL (in the quote currency) = (Closing price − Opening price) × contract size × volume (lots) — for a Buy. For a Sell, it's reversed: (Opening price − Closing price).
If the quote currency is different from your account currency, the result is converted at the current rate. Then subtract the commission (charged per side — on both opening and closing) and add or subtract any swap if you held the position overnight.
Example: you Buy 0.1 lot of EUR/USD (contract size 100,000) at 1.1000 and close at 1.1010:
(1.1010 − 1.1000) × 100,000 × 0.1 = $10 gross profit, minus commission, ± swap.
While a position is open, this shows as floating (unrealised) PnL, and your Equity = Balance + floating PnL. Once you close it, it becomes realised PnL. The exact commission and swap rates are listed on the Contract Specification page.