Dogecoin is a digital currency, but what really is a digital currency?
A digital currency is a peer-to-peer, decentralized, digital currency whose implementation relies on the principles of cryptography to validate the transactions and generation of the currency itself. -Wikipedia
A digital currency is based around a public-private key pairing. A keypair (or coin) is stored on the user's computer in a file called "wallet.dat" in a hidden directory.
Top Six Digital currenciesEdit
(The list will change rapidly/without warning - see Coinmarketcap )