Cryptocurrencies are peer-to-peer, decentralized, digital currencies whose implementation relies on the principles of cryptography to validate the transactions and generation of the currency itself. Lets explore what that means.

-Peer-to-peer refers to each node on the network being able to connect to any other node and act as both a server and a client sharing updates to the blockchain (public ledger) without the need for a central server.

-Decentralized refers to the peer-to-peer architecture of the blockchain network. Each node can act as both a server and a client, so there is no need for a central server or centralized authority, thus effectively solving fraud of all kinds.

-Digital currency, among its various names, is electronic money that acts as alternative currency in the digital realm (though now with bitcoin debit cards through visa, digital currency is as use-able as fiat currency.)

-Cryptography relies on public and private keys for security. With cryptocurrencies every transaction has to be signed by a private key for security. Due to the strong security and well understood principles of cryptography, counterfeiting digital currencies is impossible.

Bitcoin is the most widely recognized cryptocurrency.