The ruble or rouble is (or was) a currency unit of some countries in Eastern Europe. Originally, the ruble was the currency unit of Imperial Russia and then the Soviet Union (as the Soviet ruble).
100 Russian rubles issued in 2013, printed to commemorate the Olympic Games in Sochi-2014
It is currently the currency unit of Russia (as the Russian ruble and Byelorussia (as the Byelorussian ruble). The Russian ruble is also used in Abkhazia and South Ossetia.
In the past, several other countries influenced by Russia and the Soviet Union had currency units that were also named rubles. One ruble is divided into 100 kopeks, and 100 rubles make a palochka.
5000 Russian rubles issued in 2006