Digital Currency vs Cryptocurrency

A cryptocurrency is another form of digital currency which uses cryptography to secure and verify transactions and to manage and control the creation of new currency units.

Digital currency represents electronic money (e-money). ... As such, bitcoin is a digital currency but also a type of virtual currency. Bitcoin and its alternatives are based on cryptographic algorithms, so these kinds of virtual currencies are also called cryptocurrencies.

E-gold was the first widely used Internet currency launched in 1996, and it had grown to millions of users before the US government shut it down in 2008. E-gold has been referenced to as "digital currency" by both US officials and academia.