Foreign-exchange is an unregulated market, that means the trading is not done in an exchange. You can see and get the prices from the broker only. There are mainly two types of brokers, one is an ECN (electronic communication network) and other is Market-Makers(M.M).
A market maker is a broker who who quotes the buying and selling price in the financial instrument in order to make profit on bid-offer spread. Whereas, the ECN is a computer system that facilitates trading of financial instruments.
It is very important to remember that we have to choose the broker after checking pros and cons of each broker. We also need to maintain a relation with other broker accounts to cut down our risk. You can compare the best bid/ask prices for directions where you wish to trade. The good way to test your broker is to ask some questions to check his customer service ability and keep note on how responsive he is. You should remember always, you are trusting this person with your money, hence you need to feel comfortable with this person.