Crypto glossary
Short explanations of Bitcoin, blockchain, wallets, private keys, satoshis, fees and other terms, with links for further reading.
Understand the word in context
This is an introductory glossary of terms used on the site. Definitions are deliberately short; when an action depends on a technical term, continue to the guide and the exact product’s documentation.
- Bitcoin
- BTC
- Satoshi
- Blockchain
- Block
- Node
- Wallet
- Private key
- Seed phrase
- Custody
- Transaction
- Confirmation
- Network fee
- Mining
- Proof of work
- Block subsidy
- Halving
- Lightning Network
- Ethereum
- Smart contract
- Stablecoin
- Phishing
- Transaction ID
- Block explorer
- Hardware wallet
- Crypto exchange
- Capital gain
- Bitcoin Bitcoin
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A digital asset and the network used to transfer it and verify its transactions.
Full explanation: What is Bitcoin? From the digital currency to the network behind it
- BTC BTC
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The standard ticker for bitcoin. Distinguish an amount in BTC units from its value in another currency.
Full explanation: What is Bitcoin? From the digital currency to the network behind it
- Satoshi Satoshi
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A unit equal to one hundred millionth of a bitcoin. One bitcoin contains 100 million satoshis.
Full explanation: What is Bitcoin? From the digital currency to the network behind it
- Blockchain Blockchain
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Records organised into linked blocks. The validation method depends on the network.
Full explanation: What is a blockchain, and what does it actually let you verify?
- Block Block
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A unit of records containing transactions and technical information under the network’s rules.
Full explanation: What is a blockchain, and what does it actually let you verify?
- Node Node
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Software participating in a network. A full node checks transactions and blocks against the rules it enforces.
Full explanation: What is a blockchain, and what does it actually let you verify?
- Wallet Wallet
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A tool for managing access to and actions involving digital assets. Custody and responsibility models vary between products.
Full explanation: Crypto wallets: the first question is who holds the keys
- Private key Private key
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Secret information used to authorise cryptographic actions such as signing transactions. Do not include it in an enquiry to the editors.
Full explanation: Seed phrases and private keys: why are they more than a password?
- Seed phrase Seed phrase
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A sequence of words used to recover certain wallets. Follow the exact documentation and do not alter or translate the words.
Full explanation: Seed phrases and private keys: why are they more than a password?
- Custody Custody
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How access to assets is safeguarded and managed, either by you or through another party.
Full explanation: Crypto wallets: the first question is who holds the keys
- Transaction Transaction
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A record of an action under the network’s rules. In Bitcoin, a transaction can transfer value between different spending conditions.
Full explanation: Bitcoin fees and confirmations: what to check when a transaction is pending
- Confirmation Confirmation
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In Bitcoin, a transaction’s inclusion in a block and the chain’s subsequent progress determine its number of confirmations.
Full explanation: Bitcoin fees and confirmations: what to check when a transaction is pending
- Network fee Network fee
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A fee associated with executing a network transaction. It is not necessarily the same as a commercial provider’s service fee.
Full explanation: Bitcoin fees and confirmations: what to check when a transaction is pending
- Mining Mining
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The process of creating blocks through proof of work on networks using that mechanism.
Full explanation: Bitcoin mining: what miners do and what their rewards do not guarantee
- Proof of work Proof of work
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A mechanism requiring computational work to produce a result the network can verify.
Full explanation: Bitcoin mining: what miners do and what their rewards do not guarantee
- Block subsidy Block subsidy
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The newly issued coin component of a block reward, separate from transaction fees.
Full explanation: Bitcoin halving: what is cut in half and what does not change automatically
- Halving Halving
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A halving of the block subsidy under Bitcoin’s issuance rules. It does not halve a user’s balance.
Full explanation: Bitcoin halving: what is cut in half and what does not change automatically
- Lightning Network Lightning Network
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A payment network built on Bitcoin that uses channels. The specific product determines how users operate it.
Full explanation: The Lightning Network: what changes when bitcoin moves through a payment channel
- Ethereum Ethereum
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A network supporting applications and smart contracts. ETH is its native asset.
Full explanation: Ethereum, ETH and smart contracts: three concepts not to confuse
- Smart contract Smart contract
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Software running on a network, with code and state. The name does not guarantee safety or legal suitability.
Full explanation: Ethereum, ETH and smart contracts: three concepts not to confuse
- Stablecoin Stablecoin
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A token designed to track a reference value. Its peg target does not eliminate risks.
Full explanation: What is a stablecoin, and why does a dollar target not guarantee its value?
- Phishing Phishing
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An attempt to make a user disclose information or take action through impersonation or a misleading message.
Full explanation: Suspicious crypto messages: pause before clicking or transferring
- Transaction ID Transaction ID
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An identifier used to locate a transaction. Displaying it alone does not prove a commercial claim about that transaction.
Full explanation: Bitcoin fees and confirmations: what to check when a transaction is pending
- Block explorer Block explorer
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An interface displaying blockchain network data. Check which network and source it uses.
Full explanation: What is a blockchain, and what does it actually let you verify?
- Hardware wallet Hardware wallet
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A dedicated device designed to hold private keys and sign transactions while separating sensitive actions from a computer or phone. It does not store the coins themselves, which are recorded on the network, or remove the need to verify addresses and protect seed phrases. The device’s source, integrity and setup also matter for safe use.
- Crypto exchange Crypto exchange
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A service allowing digital assets to be bought, sold or exchanged. Some providers hold customer assets and keys; others have different custody arrangements. Before use, check the operating company, relevant licence or registration, fees and withdrawal terms. Being able to trade an asset does not guarantee withdrawal to every wallet or over every network.
- Capital gain Capital gain
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A gain realised on disposal of an asset, generally assessed as the difference between proceeds and the asset’s attributed cost under applicable tax rules. In crypto, exchanging for another asset may also count as disposal without a bank withdrawal. Not all activity is capital in nature: business activity may be treated differently, making records and circumstances important.