How Bitcoin works

The ledger

Bitcoin maintains a shared transaction history. A wallet derives what it can spend from that history; it does not hold physical coins or a private copy of money separate from the network.

Keys and signatures

Private keys authorize spending. A digital signature lets other participants verify authorization without learning the private key. Losing control of a key can mean losing control of the associated funds.

From transaction to block

Transactions are broadcast and can be included in blocks by miners. Nodes independently check the rules. Mining makes rewriting accepted history costly, while confirmations provide a measure of how deeply a transaction sits in that history.

Before you send

Check the destination, network, and fee. Keep recovery information offline and private. A small test transaction can help catch a destination mistake, but it does not protect against every scam.