USD/RUB

USD (US dollar)
Currency unit of the United States of America, Salvador and Marshall Islands. The main world’s reserve currency.
Issued by: Federal Reserve System (Fed)
Price dynamics depends on the interest rates of Fed, inflation and growth rates of the USA.

RUB (Russian ruble)
Currency unit of Russia which is also used on the territory of the Republic of Abkhazia, the Republic of South Ossetia. It belongs to a group of commodity currencies.
Issued by: Bank of Russia 
Price dynamics mainly depends on the oil prices.