The term "cryptocurrency" refers to a digital currency based on cryptographic protocols, which make transactions safe and extremely difficult to falsify.
The most important feature of cryptocurrencies is that they are not controlled by any central authority: the decentralized nature of the Blockchain makes these coins practically immune to interference or control by governments.
Furthermore, thanks to the combination of a public and a private key, cryptocurrencies simplify the transaction process. The exchanges take place with minimal processing costs, allowing users to avoid the very high commissions imposed by traditional financial institutions.