0 How does the B/S system work?

As with any market, for each currency pair, there are 2 prices. The difference between them is called the spread.
The spread is measured in points or pips – lowest decimal figure in a currency rate.
For a EURUSD a pip equals 0.0001 (or 10 dollars on 100.000), for EURJPY a pip equals 0.01 (or 1000 yen on 100.000).