Virtual currencies are financial innovations that have grown in number and popularity in recent years. While there is no statutory definition for virtual currency, the term refers to a digital representation of value that is not government-issued legal tender. Unlike U.S. dollars and other government-issued currencies, virtual currencies do not necessarily have a physical coin or bill associated with their circulation. While virtual currencies can function as a unit of account, store of value, and medium of exchange, they are not widely used or accepted. Some virtual currencies can only be used within virtual economies (for example, within online role-playing games) and may not be readily exchanged for government-issued currencies such as U.S. dollars, euro, or yen. Other virtual currencies may be used to purchase goods and services in the real economy and can be converted into government-issued currencies through virtual currency exchanges.