Historically the won was tied to the USD with a symbolic rate of 2.16 (the birthday of Kim Jong Il) This rate was abandoned in 2001 and the current rate is closer to 9,000 won to 1 USD.
Common banknotes in circulation are the ₩100, ₩200, ₩500, ₩1000, ₩2000, ₩5000
Coins still exist but are extremely rare and have been all but phased out.