Bitcoin (abbreviated as BTC) is a decentralized digital currency created in 2009 by an individual or team using the pseudonym Satoshi Nakamoto. Bitcoin is the first and most famous cryptocurrency, operating without reliance on a central bank or a single administrator, but rather through a distributed network of users for transaction verification and currency issuance.

Here are some key features of Bitcoin:

1. **Decentralization**: The Bitcoin network consists of nodes spread across the globe, which collectively maintain the security of the network. There is no central authority controlling the Bitcoin network.

2. **Blockchain Technology**: Bitcoin transactions are recorded on a public distributed ledger known as the blockchain. Each transaction block is cryptographically linked to the previous block, forming an ever-extending chain.

3. **Mining**: The issuance of Bitcoin is achieved through a process called “mining.” Mining involves using computational power to solve complex mathematical problems, and miners who successfully solve the problems receive newly generated bitcoins as a reward.

4. **Limited Supply**: The total supply of Bitcoin is capped at 21 million coins. This limited supply is designed to prevent inflation.

5. **Transactions**: Bitcoin can be used to purchase goods and services, or as an investment tool. Transactions can be conducted without revealing personal identity, providing a certain level of anonymity.

6. **Security**: Once a Bitcoin transaction is confirmed by the network, it is nearly impossible to reverse. This increases the security of transactions but also means that if funds are sent to the wrong address, they may not be recoverable.

7. **Volatility**: Due to various factors, including market supply and demand, regulatory environment, and technological developments, the price of Bitcoin is highly volatile.