What Is Bitcoin?

Bitcoin can mean two related things: the peer-to-peer network and the BTC unit recorded on that network. The network maintains a shared transaction history called a blockchain. BTC is the scarce digital asset transferred within that system.

No single company owns the ledger. Independent nodes verify transactions and blocks against the same public rules. A proposed transaction that breaks those rules can be rejected even if someone is willing to broadcast it.

Bitcoin ownership is controlled through cryptographic keys. A wallet helps a user manage those keys and construct transactions; it does not hold coins in the way a physical wallet holds cash. The blockchain records spendable transaction outputs associated with the conditions needed to move them.

When a transaction is broadcast, nodes check details such as signatures and whether the same funds were already spent. Miners group valid transactions into blocks. Proof of work makes adding blocks costly, while later blocks make reversing confirmed history progressively more difficult.

• A public address can receive bitcoin, while the private key authorizes spending.
• Network fees compensate miners for including transactions; they are not fixed by the amount transferred.
• A confirmation means a transaction has been included in a block, not that its market value is guaranteed.

Bitcoin's protocol limits total issuance to 21 million BTC. New bitcoin enters circulation through block rewards, and the issuance portion of that reward declines according to a programmed schedule. Transaction fees are separate from newly issued coins.

The supply rule is transparent, but scarcity alone does not determine price. Demand, liquidity, regulation, market structure, custody practices, and broader economic conditions all affect what buyers and sellers are willing to pay.

People use Bitcoin for different reasons, including transferring value, self-custody, and gaining exposure to a digitally scarce asset. Those uses depend on reliable key management and access to the network.

Trade-offs include price volatility, irreversible transactions, variable fees, limited base-layer throughput, energy use from proof of work, and the risk of losing private keys. Services that custody bitcoin introduce their own counterparty and security risks.

Bitcoin is not anonymous by default. Addresses are pseudonymous, and transaction history is public. Connecting an address to a real identity can make activity easier to trace.

A bitcoin price does not represent the value of the entire network. Market capitalization multiplies price by circulating supply, while actual liquidity depends on the orders available in specific markets. Bitcoin is also not a bank account: transactions generally cannot be reversed by a support team.