Bitcoin
Decentralized digital money secured by proof of work.
Bitcoin is a decentralized electronic cash network launched in 2009 and the name of its native asset, BTC. It lets participants transfer value without requiring a central operator to maintain balances or approve payments. A public ledger, proof-of-work consensus, and independently operated nodes enforce a predictable set of rules.
Users control bitcoin through cryptographic keys. A wallet constructs and signs a transaction that spends previously received outputs, then broadcasts it to peers. Miners collect valid transactions into candidate blocks and expend computing power to find a valid proof of work. Nodes verify the block, transaction signatures, issuance, and other consensus rules before accepting it.
Bitcoin's supply is capped by protocol rules at 21 million BTC. New coins enter circulation through the block subsidy paid to miners, which is cut approximately in half every 210,000 blocks. Transaction fees make up the other part of miner revenue. One bitcoin divides into 100 million units called satoshis, allowing payments much smaller than one BTC.
Bitcoin matters because it demonstrated that scarce digital value could be transferred on an open network without one trusted ledger owner. People use it for long-term savings, international transfers, merchant payments, and settlement. The Lightning Network supports faster, cheaper payments through channels that ultimately settle to Bitcoin, but it introduces different operational and liquidity considerations.
The network makes tradeoffs. Base-layer capacity is intentionally limited, so fees and confirmation times rise when demand for block space increases. Proof-of-work mining consumes energy, and its environmental effect depends partly on energy source, equipment, location, and alternative uses. Transactions are public and normally irreversible. Bitcoin provides pseudonymity, not automatic anonymity.
Safe use requires understanding custody. Losing a seed phrase or exposing a private key can cause permanent loss. Exchanges and custodians add counterparty risk, while self-custody adds personal responsibility. Verify the network and destination, wait for appropriate confirmations, use secure backups, and treat unexpected recovery requests as scams. Bitcoin's historical returns do not guarantee future performance, and price volatility can be severe. Distinguish the protocol's technical properties from claims that any investment product built around BTC is safe.
Tax, reporting, and payment rules vary by location, so users should keep transaction records and check current local requirements.
Frequently asked questions
- Bitcoin is a peer-to-peer digital money system and the native asset, BTC, transferred through it. No central bank or company controls the ledger. Independent nodes enforce shared rules, and miners use proof of work to order transactions. Its issuance schedule limits the eventual supply to 21 million BTC, with each bitcoin divisible into 100 million satoshis.
- Wallets sign transactions with private keys and broadcast them to the network. Miners select valid transactions, build candidate blocks, and compete through proof of work. Nodes independently verify each block and follow the chain with the most accumulated work under their rules. Confirmations make reversal increasingly difficult, while fees pay for limited block space.
- Use reputable open-source or well-reviewed wallet software, verify addresses and amounts on a trusted screen, and send a small test payment when appropriate. Protect seed phrases offline and use hardware signing for valuable holdings. Confirm whether a service uses Bitcoin mainnet, Lightning, or another network, because addresses and recovery processes differ. Avoid promises of guaranteed returns.