Kuwaiti Monetary Unit is the official currency of the State of Kuwait. It is commonly referred to as the Kuwaiti Dinar, which is the most recognized synonym for the currency. Other synonyms for the currency include KWD, KD, or simply the Dinar. Some unofficial synonyms include the "Kuwaiti Buck", the "Koupee" and the "Kuwaiti Dollar". Because of its high value and stability, the Kuwaiti Dinar is commonly used as a currency of choice for investments, foreign exchange, and tourism in the Middle East. It is also one of the most expensive currencies in the world.