Forex Currency Chart

Forex charts?
When looking at a forex chart for a currency “PAIR” you will see 2 lines one for each currency. What is the significance of the “distance” between the two lines (representing each currency)? I am using this to determine the average percentage change, daily, weekly, etc.
If you look at an FX chart there’s only one line…
http://www.dailyfx.com/charts/Chart.html …that’s an EUR/USD chart.
All charts work on the basis that 1 of the first symbol will buy you ___ of the 2nd.
Example: EUR/USD is now at 1.2811 which means one euro will get you 1.2811 dollars.
FOREX CURRENCY STRENGTH CHART – TradingFX.com Range Bar Charts
