Forex STP, Forex ECN brokers, Market Makers and no dealing desk: Different types of Forex brokers

Forex STP and Forex ECN brokers: there are different kinds of Forex brokers and even for experienced traders it is difficult to recognize the variation among them. 

MARKET MAKER: In Forex, a market maker (MM) provides liquidity for its traders by quoting bids and asking prices, and creating two-sided markets for taking long and short positions.

Market makers make profit with the spread; which is the difference between the asking prices and the bid prices. MM usually works with a dealing desk, a dealing desk is a group of traders that manage the orders that go through the market.
NDD or No dealing desk: this type of Forex broker works directly with market liquidity providers; this means that the order of an investor will go straight to the market with no intermediation and it will deal with several liquidity providers in order to get the better bid and asking prices.
ELECTRONIC COMMUNICATIONS NETWORK Forex ECN broker: This kind of broker routes the costumers order to the interbank market for execution; thus, allowing their other clients to be the counterparty to a transaction. An ECN broker provides a market place where all participants trade against each other by sending orders to the system. It is possible to see the highest bid and the lowest offer and also the actual prices. The spread is minimum or nonexistent and the broker will charge a small fee for the transactions.
STRAIGHT-THROUGH-PROCESSING Forex STP broker: This type of broker routes most orders straight to the market and sometimes they can re-quote an order if needed. Forex STP brokers are a mix between MM and Forex ECN brokers.
To have the difference in mind before choosing a Forex broker is necessary, a Forex STP broker offers little human manipulation of the customers’ orders and they usually make an intervention when it is needed. The most recommendable type is Forex ECN broker, since there is no human intervention and customers interact with each other in the market.