Types of digital currency are there:

• Ethereum (ETH), the first Bitcoin alternative on our list, is a decentralised software platform that allows smart contracts and decentralised apps (dApps) to be written and run without the need for third-party downtime, fraud, control, or intervention.
• Litecoin (LTC), which debuted in 2011, was one of the first cryptocurrencies to follow in Bitcoin's footsteps, and has been dubbed 'the silver to Bitcoin's gold.'
• Charlie Lee, an MIT graduate and former Google developer, designed it.
• Cardano (ADA) is a 'Ouroboros proof-of-stake' cryptocurrency developed by engineers, mathematicians, and cryptography professionals using a research-based approach.

Read More: How do central bank digital currencies work?