Digital currency (also known as cryptocurrency) is a virtual currency that uses cryptography to ensure security and anonymity. Unlike the legal tender used in the real world (such as US dollar, Euro, etc. ), these currencies are not introduced and issued by the government or the central bank, but a new type of currency based on distributed ledger technology (blockchain).

Digital currency can bring many changes and influences to the monetary and financial systems:

1. Anonymity and privacy: digital currency's decentralization and encryption technology ensure the anonymity and privacy of transactions, and users can avoid worrying about being eavesdropped, hacked or investigated by regulatory authorities.

2. Autonomy: The anonymity of digital currency means that users can completely own and control their own assets without authorization or recognition from banks or third-party institutions.

3. Reduce the cost of financial transactions: digital currency is global, decentralized and does not need intermediary agents, which reduces the cost and time of traditional financial transactions such as bank transfer and payment.

4. Increase the transaction speed: The transaction speed in digital currency is fast, without waiting for approval, and the time required to complete the transaction by using blockchain technology is greatly reduced.

5. Non-tampering and anti-counterfeiting: digital currency's decentralization and blockchain technology can guarantee the authenticity and non-tampering of every transaction, and digital currency will not face the risk of being forged.

In a word, digital currency's many advantages have brought unprecedented changes to the financial system, but also brought new challenges and thoughts to the fields of currency, finance and investment.