CZK

What Does CZK Mean?
The ISO 4217 currency code for the Czech koruna, the official legal tender for the Czech Republic. The Czech koruna (CZK) has been the official currency of the Republic since February 8, 1993, when it replaced the Czechoslovak koruna. The Republic planned to adopt the euro as its official currency in 2012, but opposition halted that move in 2007.

Investopedia explains CZK
The Czech National Bank (headquartered in Prague) issues the Republic's currency. It mints coins in 1, 2, 5, 10, 20 and 50 koruna denominations and prints banknotes in 50, 100, 200, 500, 1,000, 2,000 and 5,000 denominations.  

The currency market, also known as the foreign exchange market, is the largest financial market in the world.