Cryptocurrency is a form of digital or virtual currency that uses cryptography for security. The main feature that distinguishes it from traditional currencies is its decentralized nature, meaning it isn't controlled by a central authority like a government or bank. Instead, most cryptocurrencies operate on a technology called blockchain, which is a distributed ledger that records all transactions across a network of computers.

Bitcoin is the first and most well-known cryptocurrency. It was created in 2009 by an anonymous person or group of people using the name Satoshi Nakamoto. Bitcoin allows for peer-to-peer transactions without the need for intermediaries like banks. It has a capped supply of 21 million coins, which adds to its scarcity and value.

Some key features of Bitcoin and other cryptocurrencies:

1. Decentralization: No central control, and transactions are verified by a network of computers (nodes).

2. Blockchain Technology: A transparent, secure ledger that records every transaction.

3. Anonymity & Privacy: While transactions are recorded on the blockchain, participants can maintain a degree of privacy, depending on how they use the system.

4. Volatility: Cryptocurrency prices, including Bitcoin's, are known to be highly volatile, often experiencing significant fluctuations.

5. Mining: To create new bitcoins, miners use computational power to solve complex mathematical problems, securing the network and earning rewards.

Would you like to know more about how Bitcoin works, its potential uses, or something else related to cryptocurrency?