A raw spread trading account, also often called an ECN account, offers real market prices for all instruments. Forex brokers will not add any markup on asset prices, so spreads usually are extremely low or even zero. However, traders have to pay a higher commission fee for each trade executed. Some forex brokers charge the fees for each opening and closing trade ('per side'), while some others may charge fees after one full round-turn.
For example, let's assume you want to buy the EUR/USD which is currently traded at 1.2100. If you have a raw spread account, you will probably be able to buy it at 1.2100. As soon as the price rises to any level, you can close the position with considerable profit (although you have to make sure the gain will offset the commission fee as well).