In forex trading you can win in two ways. If someone has a long position on a currency pair then he/she can win by the rising of its price (appreciation of base currency relatively to quote currency). Lets say that you have bought the EUR/USD pair at 1.2257. If price goes above 1.2257 i.e. 1.2300 you win 43 pips, but if it goes below i.e. 1.2205 you lose 52 pips.

If someone has a short position on a currency pair then he/she wins from the declining of its price (depreciation of base currency relatively to quote currency). Lets say that you have shorted the EUR/USD pair at 1.2800. If price goes below 1.2800 i.e. 1.2750 you win 50 pips but if it goes above i.e. 1.2850 you lose 50 pips.