I believe you're referring to "digital currency" or "cryptocurrency." Digital currency is a form of currency that exists only in electronic or digital form. It utilizes cryptographic technology to secure and verify transactions, control the creation of new units, and facilitate the transfer of assets.

The most well-known and widely used digital currency is Bitcoin, which was introduced in 2009. Since then, numerous other cryptocurrencies have emerged, including Ethereum, Ripple, Litecoin, and many more. Each cryptocurrency operates on a decentralized network called a blockchain, which is a public ledger that records all transactions and ensures transparency.

Cryptocurrencies offer several potential advantages over traditional forms of currency. They provide faster and cheaper cross-border transactions, increased security and privacy through encryption, and greater financial inclusivity for unbanked populations. Additionally, cryptocurrencies can enable smart contracts, which are self-executing contracts with predefined conditions embedded in the blockchain.

However, it's important to note that digital currencies also come with certain risks and challenges. The value of cryptocurrencies can be highly volatile, making them subject to speculative investment behavior. They have also been associated with illicit activities due to their pseudonymous nature. Regulatory frameworks around the world are still evolving to address these concerns and provide clarity regarding their legal status and taxation.

Overall, digital currencies have the potential to revolutionize the financial landscape, but their widespread adoption and impact on the global economy are still evolving and uncertain. It's essential to conduct thorough research and exercise caution when engaging with digital currencies.