Bitcoin
An open monetary network and the BTC asset, verified by nodes and recorded in a blockchain.
Glossary
Bitcoin glossary
Short definitions for search pages, internal links and users who are new to BTC.
BTC
The ticker for bitcoin as an asset. One BTC is divisible into 100,000,000 satoshis.
Satoshi
The smallest unit of BTC. 1 satoshi equals 0.00000001 BTC.
Seed phrase
A list of words used to recover a wallet. Whoever has it can usually control the funds.
Private key
A cryptographic key used to sign transactions. It must never be shared with websites or support agents.
Public address
An address used to receive BTC. It can be shared, but reuse can reduce privacy.
Mempool
The queue of unconfirmed Bitcoin transactions waiting to be included in a block.
sat/vB
Fee rate: the number of satoshis paid per virtual byte of a transaction.
Block height
The number of a block in the Bitcoin chain, starting from the genesis block.
Halving
An event roughly every 210,000 blocks when the block subsidy is cut in half.
Full node
Software that independently verifies Bitcoin blocks and transactions.
UTXO
Unspent transaction output: the unspent pieces that make up a wallet balance.
Lightning Network
A payment network built on Bitcoin for faster and cheaper small payments.
Cold wallet
A wallet or signing device where private keys are isolated from the internet.
Hot wallet
A wallet on an internet-connected device. Convenient, but riskier for large balances.