ECN is an acronym for Electronic Communications Network. A Forex ECN broker does not have a dealing desk but instead provides a marketplace where multiple market makers, banks and traders can enter in competing bids and offers into the platform and have their trades filled by multiple liquidity providers in an anonymous trading environment. The trades are done in the name of your ECN broker, thereby providing you with complete anonymity. A trader might have their buy order filled by liquidity provider "A", and close the same order against liquidity provider "B", or have their trade matched internally by the bid or offer of another trader. The best bid and offer is displayed to the trader along with the market depth which is the combined volume available at each price. A greater number of marketplace participants providing pricing to the ECN broker leads to tighter spreads. ECN's typically charge a small fee for matching trades between their clients and liquidity providers.