There are 2 types of currency prices at Forex - Bid and Ask. The price we pay to buy the pair is called Ask. The price, at which we sell the pair, is called Bid.
Spread is the difference between these two prices. In other words, it is a commission you pay to your broker for every transaction.
SPREAD = ASK – BID
You can find the minimal and typical spread on our website's Contract specifications page.