Forex standard accounts are the most basic type of trading accounts. With this account, a trader will get a standard level of spread for all major currency pairs. With a standard account, average spread of EURUSD stays between 1 pip to 3 pips (varies brokers to brokers). The standard account does not take charges any trading commissions. Only the spreads. This standard account sometimes gets termed as "Pro Trading Account". The concept is almost same.
This type of account is very popular among all newbie or new forex traders. Good for practicing the forex market with a small amount of deposit & still getting the real feel. Cause cent account deposit starts at 0.10 cent or $1.00 only. In cent account, $1.00 equals $100. Thus if a trader deposits $10.00. He/she will see that in his/her trading account it is getting showing as $1000. Cent account spreads are same as standard account spread, some broker also provides ECN cent account with trading commission & lower spread.
ECN stands for "Electronic Communication Network". It is a type of broker to market pricing structure with lightening fast execution of trading orders. ECN orders are automatic & it gets immediately executed as soon as trader press the buy/sell button from their trading platform. ECN account usually has lower spread on major pairs compared to standard account spread. For some broker with EURUSD spread is around zero(0.0). But obviously, with ECN account, you have to pay trading commission. These trading commissions get calculated as per standard lot size. Example, $4 per lot. ECN account get widely used by the Forex Scalpers.
STP stands for "Straight Through Processing". With STP account trading speed is also faster like ECN account. Forex STP account does not have any middleman(.i.e broker) to intervene the pricing of the orders. In general, case, when a trader presses the buy button for example, broker sees his/her trading orders at the certain ask price, then broker decides the price & return the order. In case of STP account trader order get directly transferred to the bank(liquidity providers) then automatically those a best offer & return it back to the trader.
DMA stands for "Direct Market Access", where traders get direct access to the physical market. It is mostly similar to STP account types. But with DMA trader get access to the DOM (Depth of market). With Depth of Market, a trader can view all trading volume of that broker. DMA accounts are usually better for large capital traders who trade daily in bigger volume. DMA as better transparency than all other types of trading account. But usually required a higher deposit.
VIP accounts are basically a mixture of ECN, STP & DMA altogether. VIP account is broker specific special account type for larget forex investors. Deposit with this account usually starts from $50,000 with zero spread & lowest trading commissions. VIP account holders get personal account managers, who will manage your trade if you are somehow not available. Top priority on your issues. Plus VIP account holders get free subscription to many premium trading services.
Market makers are the type of brokers, who decides your orders at which price you will receive your orders. For example, if you place an sell order at the certain bid price, then market maker broker will be the middleman to judge where they should give you the order at the price you asked or in different price. Generally, most of the standard accounts are based with market makers.
Generally executions are two types:
With instant execution, when you will press the buy/sell button, your order will be sent to the broker. Will get executed instantly, if the broker has your bid/ask price available to execute. Else, you will receive a requote. You need to send your trade order again.
With Market Execution, your order will get executed directly with the liquidity providers. The broker does not interfere. Once you will send the order, your order will get in the pool of orders by different liquidity providers. From there system will automatically those the best price & will return you that price. Note, with market execution, you can not set stop loss & take profit at the time of entering the order. You can set it after that.