The Hryvnia, also spelled sometimes as Hryvna or Grivna (UAH) was introduced September 2, 1996 by the National Bank of Ukraine (NBU) and is the only legal tender in Ukraine.
There are bills for 1, 2, 5, 10, 20, 50 and 100 Hryvnias. There are coins called 'kopiyka' for 1, 2 ,5 10, 25, and 50 kopiykas. (1 kopiyka is equal to 1/100 of Hryvnia.) Also there are 1, 2 and 5 Hryvnia coins as well as some commemorative collectible coins.
Exchange booths can be found all over any busy section of town. Rates are generally as good or even better than in banks, and the service is quicker. Take note of the different exchange rates offered; beware of things like a faded "0" slipped between digits on exchange rate signs in touristy areas. No documents are necessary to exchange money at exchange booths, but passports are required in many banks, where the procedure can take a bit longer. Count the money at the window in plain sight of the money changer before walking away. More central areas tend to have better exchange rates unless their main clients are tourists. If you enter Ukraine through Kyiv's Boryspil airport, bring some smaller dollar or euro bills if you will need to pay for a taxi; the exchange point in the airport has poor exchange rates. The worst exchange rate have all the supermarkets with their own exchange boots.
Travelers are less practical than cash since they are cashed with a greater commission and only certain banks cash them. These banks may have limited hours for cashing travelers checks. ATM cards are highly practical since there are now ATM machines in every town that work around the clock and you can get local cash immediately. Credit cards are accepted in expensive restaurants, hotels, and boutiques, and increasingly in large cash&carry stores. Be discreet with your cash.