There are three main models known as the ECN, STP and Market Maker.
ECN means 'Electronic Communication Network', which is a technical term used to describe how banks and liquidity providers connect to each other to form bid and offer prices. It's used to identify providers who use this type of pricing mechanism in order to offer raw interbank pricing to retail traders. The broker will stream raw prices and your trades will be offset with another client or liquidity provider, or held internally by the broker. This usually results in faster trade execution. STP means 'Straight Through Processing' and is used when a Forex and CFD provider process all trades at market prices obtained from a liquidity provider. This price is simply passed on by the broker. Market makers normally operate a dealing desk in order to create their own prices. These prices can be based on their trading positions or overall risk exposure and may not reflect the prices in the underlying market. Vantage FX is the issuer of the products it provides.