What is Cryptocurrency?

A cryptocurrency is a medium of exchange such as the US dollar. Bitcoin, the first cryptocurrency, appeared in January 2009 and was the creation of a computer programmer using the pseudonym Satoshi Nakamoto.
Like the US dollar, cryptocurrency has no intrinsic value in that it is not redeemable for another commodity, such as gold. Unlike the US dollar, however, cryptocurrency has no physical form, is not legal tender, and is not currently backed by any government or legal entity. In addition, its supply is not determined by a central bank and the network is completely decentralized, with all transactions performed by the users of the system.
The term cryptocurrency is used because the technology is based on public-key cryptography, meaning that the communication is secure from third parties. This is a well-known (Blockchain) technology used in both payments and communication systems. A cryptocurrency (or crypto currency) is a digital asset designed to work as a medium of exchange using cryptography to secure the transactions and to control the creation of additional units of the currency. Cryptocurrencies are a subset of alternative currencies, or specifically of digital currencies.