60+ cryptocurrency terms explained simply — your complete reference for Bitcoin, blockchain, and crypto vocabulary.
Bitcoin uses dozens of technical terms that can intimidate newcomers. This glossary explains 60+ essential terms in plain English — what they mean, why they matter, and how they fit into the broader Bitcoin ecosystem.
Use the alphabet bar above to jump to any letter, or read sequentially as a primer. Every term links to related concepts so you can build your understanding step by step.
Looking for answers to specific questions? See our Bitcoin FAQ megaguide.
A Bitcoin address is a string of letters and numbers (e.g., bc1q24qa2l84ljw...) that represents a destination for receiving BTC. Think of it like an email address for money. Modern addresses start with bc1 (Bech32, SegWit), older ones with 1 (Legacy) or 3 (P2SH). Never reuse the same address twice — generating a new address per transaction improves privacy.
A free distribution of tokens to specific wallet addresses, usually as a marketing campaign for new altcoin projects. Airdrops are common in the broader crypto space but rare for Bitcoin itself. Warning: many "airdrops" are phishing scams designed to drain your wallet — never sign unfamiliar transactions or share seed phrases.
Any cryptocurrency other than Bitcoin (literally "alternative coin"). Examples include Ethereum, Solana, Cardano, and thousands more. Bitcoiners often distinguish BTC as digital money/store-of-value while viewing altcoins as speculative tech experiments. See also: Shitcoin.
A set of regulations requiring exchanges and financial services to prevent illicit money flows. AML rules drive KYC verification on exchanges. In the EU, AML compliance is part of the MiCA framework as of December 2024.
The highest price an asset has ever reached. Bitcoin's ATH history (in USD, approximate): $20K in 2017, $69K in 2021, $73K in 2024, and over $100K in 2025. ATHs are often followed by sharp corrections — a normal part of Bitcoin's halving-driven cycles.
A peer-to-peer exchange of one cryptocurrency for another without an intermediary, executed in a single atomic transaction (either fully completes or fully fails). Enabled by hash time-locked contracts (HTLCs). Atomic swaps preserve self-custody and remove counterparty risk.
The first and largest cryptocurrency, launched in January 2009 by the pseudonymous Satoshi Nakamoto. Bitcoin is a peer-to-peer electronic cash system with a fixed supply cap of 21 million coins, secured by Proof-of-Work mining. The smallest unit is the satoshi (0.00000001 BTC).
A formal document proposing changes to the Bitcoin protocol. Notable BIPs include BIP-39 (seed phrases), BIP-44 (HD wallet structure), BIP-141 (SegWit), and BIP-340/341 (Taproot). BIPs are reviewed openly on GitHub before activation.
A bundle of validated Bitcoin transactions added to the blockchain roughly every 10 minutes. Each block contains up to ~4 MB of data, references the previous block (via its hash), and rewards the miner with new BTC plus transaction fees.
A distributed, append-only ledger of all Bitcoin transactions, replicated across thousands of nodes worldwide. Each block is cryptographically chained to the previous one, making historical tampering computationally infeasible. The Bitcoin blockchain has run continuously since 2009 with ~99.99% uptime.
A web tool for searching the Bitcoin blockchain — view any address balance, transaction status, block details, and fee rates. Popular explorers: mempool.space, blockstream.info, blockchain.com.
The newly minted BTC paid to a miner who successfully adds a block to the chain, plus all transaction fees in that block. The reward halves roughly every 4 years (see Halving). It started at 50 BTC in 2009 and is currently 3.125 BTC after the April 2024 halving.
Storing Bitcoin private keys completely offline — typically on a hardware wallet, paper wallet, or air-gapped computer. Cold storage is the gold standard for long-term holdings since it eliminates online attack surfaces. Opposite of hot wallet.
When a Bitcoin transaction is included in a block, it has 1 confirmation. Each subsequent block adds another confirmation, exponentially decreasing the chance of reversal. Most exchanges require 3-6 confirmations (~30-60 minutes) before crediting deposits. For very large amounts, 6+ is standard.
The agreement among Bitcoin nodes about which transactions are valid and which chain represents the truth. Bitcoin uses Nakamoto consensus — the longest valid chain (most accumulated PoW) wins.
A wallet where a third party (usually an exchange) controls the private keys on your behalf. Convenient but risky — exchanges can freeze accounts, get hacked, or go bankrupt (see Mt. Gox, FTX). The opposite is a self-custodial or non-custodial wallet.
An investment strategy where you buy a fixed amount of Bitcoin on a regular schedule (e.g., €100 every Friday), regardless of price. DCA smooths out volatility, removes emotional timing decisions, and historically outperforms most active trading. Recommended for most long-term Bitcoiners.
The distribution of control across many independent participants rather than a central authority. Bitcoin's decentralization comes from thousands of full nodes, miners spread globally, and an open protocol no single entity governs. This makes Bitcoin censorship-resistant and politically neutral.
A measure of how hard it is to mine a new block. Bitcoin auto-adjusts difficulty every 2,016 blocks (~2 weeks) so blocks are produced about every 10 minutes regardless of total network hash rate. As mining grows, difficulty rises proportionally.
Spending the same Bitcoin twice. Bitcoin's blockchain prevents this by requiring miners to validate every input — once a transaction is confirmed, attempting to spend the same UTXO again will be rejected by the network. Bitcoin solved double-spending without trust, a problem unsolved for digital cash before 2009.
An investment fund traded on stock exchanges. Spot Bitcoin ETFs (approved in the US in January 2024 — IBIT, FBTC, ARKB) hold actual BTC, letting investors gain exposure through brokerage accounts. Convenient for retirement accounts but you don't control private keys — see self-custody.
A platform that allows you to trade fiat money (EUR, USD, CZK) for Bitcoin and other cryptocurrencies. European examples: Coinbase, Bitpanda, Anycoin, Binance, Bison, Young Platform, Zonda. All EU exchanges are now MiCA-licensed.
Government-issued currency not backed by a physical commodity (EUR, USD, CZK, GBP). Fiat derives value from government decree and economic trust. Bitcoiners often contrast fiat's unlimited supply (and inflation) with Bitcoin's hard-capped 21 million supply.
The amount paid to miners to include your transaction in a block. Measured in sats per virtual byte (sat/vB). Higher fees = faster confirmation. Fees fluctuate with network demand. As the block reward halves over time, fees become miners' primary income.
The emotional urge to buy Bitcoin during sharp price rallies, fearing further upside. FOMO buying near local tops is a classic mistake. Antidote: DCA on a fixed schedule.
Negative narratives about Bitcoin spread by media, governments, or competitors — often with selective or outdated framing (energy use, "Bitcoin is dead", regulatory bans). Bitcoin has been "declared dead" 470+ times since 2010 and continues running.
A computer running Bitcoin Core software that downloads, validates, and stores the entire blockchain (~600 GB in 2026). Full nodes enforce consensus rules and secure the network. Anyone with a Raspberry Pi can run one — Umbrel and Start9 make setup easy.
The first block of the Bitcoin blockchain, mined by Satoshi Nakamoto on January 3, 2009. It famously embeds the text "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks" in its coinbase, marking Bitcoin's anti-establishment origins.
An event every 210,000 blocks (~4 years) where Bitcoin's block reward is cut in half. Past halvings: 50→25 BTC (2012), 25→12.5 (2016), 12.5→6.25 (2020), 6.25→3.125 (April 2024). The next halving (3.125→1.5625) is scheduled for ~2028. Halvings reinforce Bitcoin's supply scarcity and historically precede major bull markets.
A small physical device that stores Bitcoin private keys offline and signs transactions internally — the most secure self-custody option. Top brands: Trezor, Ledger, Coldcard, BitBox. Recommended for any holding above ~€1,000.
A fixed-length cryptographic fingerprint of arbitrary input data, produced by a one-way function (Bitcoin uses SHA-256). Hashes are used to chain blocks, validate transactions, and prove computational work. Even a tiny change in input creates a completely different hash.
The total computational power securing the Bitcoin network, measured in hashes per second (currently ~700 Exahash/s in 2026). A higher hash rate means Bitcoin is harder to attack — securing 51% would require billions of dollars in mining hardware and electricity.
A misspelling of "hold" from a famous 2013 Bitcointalk forum post that became the rallying cry of long-term Bitcoin holders. Backronymed to "Hold On for Dear Life." Embodies the strategy of buying and holding through volatility rather than trading.
A Bitcoin wallet connected to the internet — mobile apps (BlueWallet, Phoenix), desktop apps (Sparrow, Electrum), or exchange wallets. Convenient for spending but more exposed to hacking. Use hot wallets for small amounts only; keep savings in cold storage.
Identity verification required by exchanges to comply with AML regulations. Typically involves uploading a government-issued ID, a selfie, and proof of address. EU exchanges under MiCA require KYC for all clients buying or selling Bitcoin.
A Layer 2 scaling solution built on Bitcoin enabling near-instant, low-fee payments through off-chain payment channels. Capacity exceeds 5,000 BTC across 70,000+ channels in 2026. Used for micro-tipping, retail payments, and cross-border remittances. Apps: Phoenix, Wallet of Satoshi, Muun, Strike.
(1) A historical record of all transactions — the Bitcoin blockchain is a distributed ledger. (2) Ledger SAS, a French manufacturer of popular hardware wallets (Nano S, Nano X, Stax). Often compared to Trezor.
A protocol that lets you generate dynamic Lightning invoices and static payment addresses. LNURL-pay supports tip jars, paywalls, and reusable Lightning addresses (e.g., [email protected]). Powers most modern Lightning UX.
The "memory pool" of unconfirmed Bitcoin transactions waiting to be picked up by miners. When the mempool is full, fees rise sharply. Real-time visibility at mempool.space.
The EU's comprehensive regulatory framework for cryptocurrencies, fully active since December 2024. MiCA requires all crypto service providers (exchanges, custodians) to obtain a CASP license, protect client assets, and comply with AML/KYC. It harmonizes rules across all 27 EU member states.
The process of using specialized hardware (ASICs) to solve cryptographic puzzles and add new blocks to the Bitcoin blockchain. Miners earn the block reward plus transaction fees. Mining secures the network through Proof-of-Work.
A wallet setup requiring multiple keys to authorize a transaction (e.g., 2-of-3, 3-of-5). Multisig dramatically improves security: a thief needs multiple devices, and you can recover from one lost key. Popular tools: Sparrow Wallet, Casa, Unchained.
A computer running Bitcoin software that participates in the network. Full nodes validate the entire blockchain; light/SPV nodes verify only headers. The more nodes, the more decentralized and resilient Bitcoin becomes.
A foundational Bitcoin principle: if you don't control the private keys, you don't truly own the BTC — you have an IOU. Coined by Andreas Antonopoulos. Reinforced by collapses of Mt. Gox, Celsius, FTX where users lost everything.
A Bitcoin script opcode allowing up to 80 bytes of arbitrary data in a transaction output. Used for timestamping documents, proof-of-existence, ordinals/inscriptions, and on-chain messaging. The output is provably unspendable.
A printout of a Bitcoin private key and address — historically a popular cold storage method. Largely obsolete today: paper degrades, single-key designs lack redundancy, and users often make import mistakes. Use a hardware wallet instead.
A 256-bit secret number that allows the owner to spend Bitcoin from a corresponding address. Anyone with the private key controls those funds — never share it. In practice, you back up a seed phrase instead, which derives all your private keys.
The consensus mechanism where miners expend computational energy to add blocks. PoW makes attacking Bitcoin economically irrational — you'd need to control 51% of global hash rate, costing billions and burning more energy than the rewards justify. Critics cite energy use; proponents note ~60%+ of Bitcoin mining uses renewable or stranded energy.
A standard format (BIP-174) for collaborative transaction signing — essential for multisig and air-gapped hardware wallets. The transaction is built, partially signed, then passed between devices/cosigners until fully signed and broadcast.
A cryptographic key derived from the private key, used to verify signatures. Bitcoin addresses are derived from public keys via hashing. Sharing a public key is safe; sharing a private key is catastrophic.
A feature (BIP-125) that lets you replace an unconfirmed transaction with a higher-fee version to speed up confirmation. Most modern wallets enable RBF by default. The new transaction must spend the same inputs and pay a higher fee.
The pseudonymous creator of Bitcoin who published the white paper in October 2008 and mined the genesis block in January 2009. Identity unknown. Disappeared from public communication in late 2010. Estimated to hold ~1 million BTC (never moved). The unit "satoshi" is named after them.
The smallest unit of Bitcoin, equal to 0.00000001 BTC (1/100,000,000). At €100,000 per BTC, 1 sat = 0.001 cents. As Bitcoin's price rises, sats become the natural denominator for everyday amounts. "Stacking sats" = accumulating Bitcoin gradually.
A list of 12 or 24 ordinary English words (BIP-39) that backs up your entire wallet. The seed deterministically derives every private key in the wallet. Store it physically (paper, steel plates) — never digitally. Anyone who reads your seed phrase owns your Bitcoin.
A Bitcoin upgrade activated in 2017 (BIP-141) that increased effective block capacity and fixed transaction malleability. SegWit addresses start with bc1q (Bech32). They reduce fees by ~30-40% compared to Legacy addresses.
Holding your own Bitcoin private keys instead of relying on an exchange or custodian. Self-custody is the default Bitcoin design — the alternative undermines the entire premise. Tools: Trezor, Ledger, Sparrow, Electrum, BlueWallet.
A pejorative term for any cryptocurrency Bitcoiners view as having no real value, weak fundamentals, or VC-backed token economics. Used liberally and often with hyperbole. See also: Altcoin.
A lightweight method of verifying Bitcoin transactions without downloading the full blockchain. SPV wallets (e.g., Electrum, BlueWallet) only download block headers (~80 MB). Tradeoff: less privacy and weaker security than running a full node.
A token pegged to a fiat currency (USDT, USDC) or commodity. Stablecoins solve volatility for traders and remittances but are usually centrally issued and freezable — unlike Bitcoin. Under MiCA, stablecoins face strict reserve and licensing rules.
A 2021 Bitcoin upgrade (BIPs 340-342) that improved privacy, scripting flexibility, and signature efficiency via Schnorr signatures. Taproot addresses start with bc1p. Enables advanced features like more efficient multisig and Lightning channel closures.
A separate Bitcoin network where coins have no real value, used for testing wallets, smart contracts, and applications. Testnet BTC is freely available from "faucets." Mainnet = real Bitcoin; Testnet = practice mode.
A signed message moving Bitcoin from one or more inputs to one or more outputs. Transactions are broadcast to the mempool, then confirmed when included in a block. Each TX has a unique 64-character TXID.
A pioneering hardware wallet manufacturer founded in Prague, Czech Republic in 2013. Models include Trezor One, Model T, Safe 3, Safe 5, and Safe 7. Open-source firmware and a strong reputation for security make Trezor a top choice for self-custody. Buy Trezor →
Bitcoin's accounting model: instead of "balances," each address holds a set of UTXOs (chunks of BTC from past incoming transactions). When you send BTC, you spend whole UTXOs and create new ones. Privacy-aware users practice "UTXO management" to avoid linking unrelated coin lots.
Software or hardware that stores and manages your Bitcoin private keys, generates addresses, and signs transactions. Wallets don't actually "hold" coins — coins live on the blockchain; wallets hold the keys to spend them. See also: Hardware Wallet, Hot Wallet, Cold Storage.
An entity holding a very large amount of Bitcoin — typically defined as 1,000+ BTC. Whales can move markets when they buy or sell. Major whales include MicroStrategy, BlackRock (via IBIT), Satoshi (~1M BTC unmoved), Binance cold wallets, and various ETF custodians.
The 9-page document published by Satoshi Nakamoto on October 31, 2008, titled "Bitcoin: A Peer-to-Peer Electronic Cash System." It describes how Bitcoin works without central authorities. Required reading: bitcoin.org/bitcoin.pdf.
Now that you understand the terms, learn how to actually buy Bitcoin in Europe — step by step.