What are short and long positions in forex?  

Short positions are taken when a trader sells currency in anticipation of a downturn in price. Making this move allows the investor to benefit from a decline. Long positions are taken when a trader buys a currency at a low price in anticipation of selling it later for more. Making these moves allows the investor to benefit from changing market prices. Remember! Since currencies are traded in pairs, every forex position inevitably requires the investor to go short in one currency and long in the other.