Benefits of ECN
ECN means electronic-communication-network and let forex traders access the real foreign exchange market.
Most traders use a market maker broker, meaning that they take the opposite of your trades. They dont have any liquidty from the interbank market, where forex is really traded.
When you lose, they profit, and vice versa. This is a conflict of interest that you usually want to avoid if you are taking your trading seriously.
Other benefits can include:
Capital at risk. Losses may exceed deposits.