The spread is the difference between the ASK price and the BID price.
BID price is the rate at which you can sell a currency pair.
ASK price the rate at which you can buy a currency pair.
You are trading EURUSD:
Bid Price: 1.18144 / Ask price: 1.18161; hence the spread will be 1.7 pips or 17 points. You can see this on your market watch on the MT4.
Pip (Percentage in point) is the smallest commonly quoted change of an exchange rate of a currency pair.