Le glossaire Bitcoin
Chaque terme employé sur ce site, défini en langage clair. Lorsqu’un terme est régulièrement mal interprété — et beaucoup des plus cités le sont — l’entrée le dit explicitement, car savoir ce qu’un chiffre ne peut pas étayer compte davantage que connaître sa définition.
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A
Adresses actives
The count of unique addresses appearing in transactions over a period, usually one day.
Keys & custodyAddress
A string encoding the conditions under which an output can be spent. Bitcoin's equivalent of an account number, except you can…
MarchésAltcoin
Any cryptocurrency other than Bitcoin.
MarchésAll-time high (ATH)
The highest price an asset has ever traded at, in a stated currency.
B
Bear market
A sustained period of falling prices and weak sentiment. In Bitcoin these have historically lasted a year or more.
RéseauBIP
A Bitcoin Improvement Proposal: the numbered document format used to specify and discuss protocol and standards changes.
Les basesBitcoin
A peer-to-peer settlement network and the fixed-supply digital asset it issues, operating without a company, an operator or an…
RéseauBitcoin Core
The reference implementation of the Bitcoin protocol, run by the large majority of full nodes.
Comment ça marcheBloc
A batch of transactions accepted into the ledger together, produced roughly every ten minutes and limited to about four million…
RéseauBlock explorer
A web tool for inspecting blocks, transactions, addresses and mempool state.
Comment ça marcheBlock height
The number of blocks in the chain before the current one, counting the genesis block as zero. It is the network's canonical clock.
EconomicsRécompense de bloc
The newly issued bitcoin paid to the miner of each block. It began at 50 BTC and halves every 210,000 blocks.
Comment ça marcheBlockchain
The append-only chain of blocks that records every Bitcoin transaction, where each block commits to the one before it by hash.
MarchésBull market
A sustained period of rising prices and strong sentiment.
MarchésDominance de Bitcoin
Bitcoin's market capitalisation as a share of the total reported crypto market capitalisation.
C
Centralisation risk
The concentration of mining, custody, development or infrastructure into few enough hands to create a systemic weakness.
Comment ça marcheChange output
The output that returns leftover value to the sender when a spent UTXO is larger than the amount being sent.
On-chain dataOffre en circulation
The quantity of bitcoin that has been mined, verifiable directly against the issuance schedule.
Keys & custodyCoin control
A wallet feature that lets you choose which specific UTXOs a transaction spends.
MiningCoinbase transaction
The first transaction in every block, which creates the block subsidy and pays it, plus the block's fees, to the miner.
Keys & custodyCold storage
Keeping keys entirely offline, so no network-connected system ever holds the secret.
Comment ça marcheConfirmation
A block containing your transaction. Each subsequent block adds another, making reversal exponentially more expensive.
RéseauConsensus rules
The validity conditions every node enforces: issuance schedule, signature validity, block weight, and everything else that makes…
EconomicsCounterparty risk
The risk that the other side of an arrangement fails to deliver — an exchange, a custodian, a lender.
Transactions & feesCPFP (child pays for parent)
Unsticking a low-fee transaction by spending its output in a new, high-fee transaction, making the pair attractive together.
Keys & custodyCustodial
An arrangement where a third party holds the keys and you hold a claim against them.
Security & scamsCommon Bitcoin scams
Recurring fraud patterns: fake giveaways, impersonated support, romance-investment schemes, fake exchanges and pre-seeded…
D
Dollar-cost averaging (DCA)
Buying a fixed amount at regular intervals regardless of price, so purchases average out over time.
MiningDifficulté
The parameter setting how hard it is to find a valid block, adjusted every 2,016 blocks to keep the average interval near ten…
MiningDifficulty adjustment
The recalculation of the mining target that happens every 2,016 blocks, roughly every two weeks.
On-chain dataDormant supply
Coins that have not moved for a long period, often used as a proxy for long-term holding or permanent loss.
Comment ça marcheDouble-spend
Spending the same coins twice. Preventing it without a trusted third party is the problem Bitcoin was built to solve.
MarchésDrawdown
The decline from a peak to a subsequent trough, usually expressed as a percentage.
Transactions & feesDust
A UTXO so small that spending it would cost more in fees than it is worth.
Keys & custodyDigital signature
Cryptographic proof that the holder of a private key authorised a specific transaction, verifiable by anyone with the public key.
E
F
Fee market
The auction for finite block space, in which users bid fee rates and miners include the highest bids.
Transactions & feesTaux de frais (sat/vB)
What a transaction pays per virtual byte of the space it occupies. Miners prioritise by fee rate, not by total fee.
RéseauFull node
A node that downloads and validates the entire chain from genesis rather than trusting anyone else's summary of it.
G
H
Halving
The scheduled 50% reduction of the block subsidy, occurring every 210,000 blocks — roughly every four years.
RéseauHard fork
A rule change that loosens what is valid, so old nodes reject the new blocks and the chain splits unless everyone upgrades.
Keys & custodyHardware wallet
A dedicated device that stores private keys and signs transactions without exposing the keys to an internet-connected computer.
Comment ça marcheHash
A fixed-length fingerprint of arbitrary data. Bitcoin uses SHA-256: the same input always gives the same output, and any change…
MiningHashrate
The estimated total computing power searching for Bitcoin blocks, usually quoted in exahashes per second (EH/s).
Keys & custodyHD wallet
A hierarchical deterministic wallet, where an unlimited tree of keys is derived from one seed.
On-chain dataHODL waves
A chart banding the supply by how long each coin has been sitting unmoved.
I
L
M
Market cycle
The observed pattern of multi-year expansions and contractions in Bitcoin's price, often anchored to the halving schedule.
MarchésMarket capitalisation
Spot price multiplied by circulating supply. A convenient comparison figure, not a measure of money invested.
Transactions & feesMempool
The set of valid transactions a node has seen but that are not yet in a block — the queue competing for block space.
Comment ça marcheMerkle root
A single hash in the block header that commits to every transaction in the block, built by hashing transactions together in pairs…
MiningMining
The process of assembling candidate blocks and searching for a valid proof of work, rewarded with the block subsidy plus…
MiningMining pool
A coordinator that combines many miners' hashrate and distributes rewards proportionally, smoothing income that would otherwise…
Keys & custodyMultisig
A spending condition requiring several signatures out of a set, such as two of three.
N
Node
A computer running Bitcoin software that independently validates every block and transaction against the consensus rules.
MiningNonce
A 32-bit field in the block header that miners vary to change the header's hash while searching for a valid block.
Keys & custodyNot your keys, not your coins
The maxim that coins held by a third party are that party's coins and your claim against them.
O
P
Payment channel
A two-party contract funded by an on-chain transaction, inside which balances can be updated repeatedly without touching the…
Security & scamsPhishing
Tricking someone into revealing secrets or authorising a transfer by impersonating a service they trust.
MarchésDimensionnement de position
Deciding how much to commit to a position based on how much you are prepared to lose if it goes against you.
Security & scamsPrivacy (on-chain)
Bitcoin is pseudonymous, not anonymous: every transaction is public forever, and addresses can often be linked to identities.
Keys & custodyPrivate key
The secret number that authorises spending from an address. Whoever holds it controls the coins, unconditionally.
MarchésProof of reserves
An attempt by a custodian to demonstrate cryptographically that it holds the bitcoin it claims to hold.
Comment ça marcheProof of work
The mechanism that secures Bitcoin: miners must find a hash below a difficulty target, which is expensive to produce and trivial…
Keys & custodyPublic key
The value derived from a private key that lets anyone verify a signature without learning the key itself.
R
RBF (replace-by-fee)
A signalling mechanism that lets an unconfirmed transaction be replaced by a version paying a higher fee.
On-chain dataCapitalisation réalisée
A valuation that prices each coin at the value it last moved at, rather than at current spot.
Comment ça marcheReorganisation (reorg)
When nodes switch to a different chain with more accumulated work, discarding one or more recently accepted blocks.
MarchésGestion du risque
Deciding in advance how much can be lost, and structuring positions so that no single outcome is ruinous.
Lightning & scalingRouting (Lightning)
Finding a path of channels with enough liquidity in the right direction to carry a payment from sender to recipient.
S
Spot Bitcoin ETF
An exchange-traded fund holding bitcoin directly, giving regulated exposure without the holder ever touching a key.
Les basesSatoshi (sat)
The smallest unit of bitcoin: one hundred-millionth of a BTC. There are 100,000,000 satoshis in one bitcoin.
Les basesSatoshi Nakamoto
The pseudonym of Bitcoin's creator, who published the white paper in 2008, released the software in 2009, and stopped…
EconomicsScarcity
Bitcoin's fixed and verifiable supply limit, enforced by every node rather than promised by an issuer.
EconomicsBudget de sécurité
Total miner revenue — subsidy plus fees — which sets how expensive it would be to attack the chain.
Keys & custodySeed phrase
Twelve or twenty-four words from which every key in a wallet is derived. Anyone with the words has the coins.
RéseauSegWit
A 2017 soft fork that moved signature data into a separate witness structure, fixing transaction malleability and effectively…
Keys & custodySelf-custody
Holding your own private keys rather than trusting a third party to hold coins for you.
Lightning & scalingSidechain
A separate chain with its own rules, pegged to Bitcoin so coins can move between them under a trust or security assumption.
MarchésSlippage
The difference between the price you expected and the price you actually got.
Security & scamsSocial engineering
Manipulating a person rather than attacking a system — the most effective attack vector in Bitcoin by a wide margin.
RéseauSoft fork
A rule change that tightens what is valid, so old nodes still accept new blocks.
MarchésSpread
The gap between the highest bid and the lowest ask. A direct cost of trading.
RéseauSPV (simplified payment verification)
Verifying that a transaction is in a block using merkle proofs, without downloading the full chain.
MarchésStock-to-flow
A model relating an asset's existing supply to its annual new production, applied to Bitcoin to argue for scheduled price…
T
Taproot
A 2021 soft fork adding Schnorr signatures and a scheme that makes complex spending conditions look like ordinary single-key…
Les basesTimechain
An alternative name for the blockchain, drawn from Bitcoin's original source comments, emphasising that its function is ordering…
Comment ça marcheTransaction
A signed instruction consuming one or more UTXOs and creating new ones. Once confirmed it cannot be reversed.
On-chain dataTransactions per day
Confirmed on-chain transactions in a 24-hour period.
U
V
W
Poursuivre l’exploration
Le Signal Bitcoin
Prix, frais, hashrate, halving et fondamentaux on-chain — chacun avec ce qu'il peut et ne peut pas vous dire.
RéférenceGlossaire Bitcoin
Chaque terme employé sur ce site, défini simplement, sans jargon et sans rien à vendre.
AnalyseL’Analyse par principes premiers
Affirmation, preuves, raisonnement — et un exposé explicite de ce que les preuves ne démontrent pas.