# Crypto Glossary: Plain-English Definitions

> A curated set of 159 plain-English crypto definitions sourced from the What The Block! dictionary. The full What The Block! catalogue covers more than 2,000 terms.

Canonical URL: https://fudfomo.co/glossary
Source: What The Block! Dictionary v1.0 (last updated 2026-04-25), browsable at https://wtb.fudfomo.co.

## Terms

- [51% Attack](https://fudfomo.co/glossary/51-attack): An attack where one party controls more than half of a network's mining power or stake and can rewrite recent history.
- [Address](https://fudfomo.co/glossary/address): A short string of characters that identifies a wallet on a blockchain.
- [Address Poisoning](https://fudfomo.co/glossary/address-poisoning): A scam that fills your transaction history with addresses that look almost like ones you trust, so you copy the wrong one.
- [Aggregator](https://fudfomo.co/glossary/aggregator): A service that scans many DEXes or lending markets to find you the best rate.
- [Airdrop](https://fudfomo.co/glossary/airdrop): A free distribution of new tokens to a list of wallet addresses. Often used to reward early users.
- [AML](https://fudfomo.co/glossary/aml): Anti-money laundering. The rules and checks that stop crypto being used to hide the origin of dirty money.
- [AMM](https://fudfomo.co/glossary/amm): Automated market maker. The smart contract behind a DEX that prices trades based on the size of two token pools.
- [Approval Phishing](https://fudfomo.co/glossary/approval-phishing): A scam where you sign a transaction that grants an attacker permission to move tokens out of your wallet.
- [APR](https://fudfomo.co/glossary/apr): Annual percentage rate. The yearly return on a deposit, before compounding.
- [APY](https://fudfomo.co/glossary/apy): Annual percentage yield. The yearly return on a deposit, including the effect of compounding.
- [ATH](https://fudfomo.co/glossary/ath): All-time high. The highest price an asset has ever reached.
- [Basis](https://fudfomo.co/glossary/basis): The difference between the spot price of an asset and its futures price.
- [Bid-Ask Spread](https://fudfomo.co/glossary/bid-ask-spread): The gap between the highest price buyers will pay and the lowest price sellers will accept.
- [BIP](https://fudfomo.co/glossary/bip): Bitcoin Improvement Proposal. The Bitcoin equivalent of an EIP, used to propose changes to Bitcoin.
- [Bitcoin](https://fudfomo.co/glossary/bitcoin): The first cryptocurrency. A digital money you can send anywhere in the world without a bank, secured by a network of computers.
- [Block](https://fudfomo.co/glossary/block): A bundle of transactions added to a blockchain together.
- [Block Explorer](https://fudfomo.co/glossary/block-explorer): A website that lets you look up transactions, addresses, and blocks on a blockchain.
- [Block Height](https://fudfomo.co/glossary/block-height): The number of blocks that have been added to a blockchain since its very first one.
- [Block Reward](https://fudfomo.co/glossary/block-reward): The newly minted coins given to whoever produces a new block.
- [Blockchain](https://fudfomo.co/glossary/blockchain): A shared digital record of transactions that no single person or company controls. Everyone can read it, and changes are extremely hard to fake.
- [Bridge](https://fudfomo.co/glossary/bridge): A tool that lets you move tokens from one blockchain to another.
- [Burning](https://fudfomo.co/glossary/burning): Permanently destroying tokens by sending them to an address nobody can spend from. Reduces supply.
- [Capital Gains](https://fudfomo.co/glossary/capital-gains): The profit you make when you sell an asset for more than you paid. Usually taxable.
- [CBDC](https://fudfomo.co/glossary/cbdc): Central Bank Digital Currency. A digital version of a country's official money issued by its central bank.
- [Centralised](https://fudfomo.co/glossary/centralised): Run or controlled by a single party. The opposite of decentralised.
- [CEX](https://fudfomo.co/glossary/cex): A centralised exchange. A regulated platform where you buy and sell crypto using an account.
- [Circulating Supply](https://fudfomo.co/glossary/circulating-supply): How many coins or tokens are actually in the market right now and free to trade.
- [Cold Storage](https://fudfomo.co/glossary/cold-storage): Keeping crypto on a device that is not connected to the internet. Safer for long-term holding.
- [Collateral](https://fudfomo.co/glossary/collateral): An asset you lock up to back a loan. If the loan is not repaid, the collateral can be taken.
- [Confirmation](https://fudfomo.co/glossary/confirmation): A measure of how many blocks have been added on top of a transaction's block. More confirmations mean stronger settlement.
- [Consensus](https://fudfomo.co/glossary/consensus): The way a blockchain's computers agree on which transactions are valid and which version of the ledger is correct.
- [Cryptocurrency](https://fudfomo.co/glossary/cryptocurrency): Digital money that lives on a blockchain instead of in a bank account.
- [Custody](https://fudfomo.co/glossary/custody): Who holds your crypto and the keys to it. Self-custody means you do, custodial means a company does.
- [DAO](https://fudfomo.co/glossary/dao): Decentralised autonomous organisation. A group whose decisions and treasury are managed on a blockchain.
- [DApp](https://fudfomo.co/glossary/dapp): A decentralised application. A web app whose backend logic runs on smart contracts.
- [Data Availability](https://fudfomo.co/glossary/data-availability): The guarantee that the data behind a block can actually be read and reconstructed by anyone.
- [Decentralised](https://fudfomo.co/glossary/decentralised): Spread across many independent participants, with no single point of control.
- [DeFi](https://fudfomo.co/glossary/defi): Decentralised finance. Apps that offer lending, trading, and saving on a blockchain instead of through a bank.
- [DEX](https://fudfomo.co/glossary/dex): A decentralised exchange. Trade crypto directly from your wallet, without an account.
- [Dusting Attack](https://fudfomo.co/glossary/dusting-attack): Sending tiny amounts of crypto to many wallets to track or de-anonymise their owners.
- [EIP](https://fudfomo.co/glossary/eip): Ethereum Improvement Proposal. The format used to suggest, debate, and document changes to Ethereum.
- [ERC-1155](https://fudfomo.co/glossary/erc-1155): A multi-token Ethereum standard that supports both fungible and non-fungible items in one contract.
- [ERC-20](https://fudfomo.co/glossary/erc-20): The Ethereum standard for fungible tokens. Most stablecoins and project tokens follow it.
- [ERC-721](https://fudfomo.co/glossary/erc-721): The Ethereum standard for non-fungible tokens (NFTs).
- [Ethereum](https://fudfomo.co/glossary/ethereum): A blockchain that lets developers build apps and issue tokens. Often called a programmable money platform.
- [EVM](https://fudfomo.co/glossary/evm): The Ethereum Virtual Machine. The runtime that executes smart contracts on Ethereum and other compatible chains.
- [Exit Scam](https://fudfomo.co/glossary/exit-scam): When the people running a project disappear with users' money.
- [FATF](https://fudfomo.co/glossary/fatf): The Financial Action Task Force. The global standard-setter for anti-money-laundering and counter-terrorist-financing rules.
- [FCA](https://fudfomo.co/glossary/fca): The UK's Financial Conduct Authority. The regulator that authorises crypto firms in the UK.
- [Finality](https://fudfomo.co/glossary/finality): The point at which a transaction is considered settled and unlikely to be reversed.
- [FinCEN](https://fudfomo.co/glossary/fincen): The US Financial Crimes Enforcement Network. The agency that enforces anti-money-laundering rules in the United States.
- [Flash Loan](https://fudfomo.co/glossary/flash-loan): A loan that is borrowed and repaid inside a single blockchain transaction. No collateral needed.
- [FOMO](https://fudfomo.co/glossary/fomo): Fear of missing out. The feeling that drives people to buy after a price has already moved a lot.
- [Fork](https://fudfomo.co/glossary/fork): A change to a blockchain's rules. Sometimes minor, sometimes big enough to split the network in two.
- [Fraud Proof](https://fudfomo.co/glossary/fraud-proof): Evidence that an optimistic rollup batch was invalid, used to roll back the bad batch.
- [Front-Running](https://fudfomo.co/glossary/front-running): Profiting by placing your own transaction ahead of someone else's pending trade.
- [FUD](https://fudfomo.co/glossary/fud): Fear, uncertainty, and doubt. Used to describe negative information, real or otherwise, that hurts confidence.
- [Funding Rate](https://fudfomo.co/glossary/funding-rate): A periodic payment between long and short perpetual futures traders that keeps the contract close to spot.
- [Futures](https://fudfomo.co/glossary/futures): A contract to buy or sell an asset at a fixed price on a future date.
- [Gas](https://fudfomo.co/glossary/gas): The unit a blockchain uses to measure how much work a transaction takes.
- [Gas Fee](https://fudfomo.co/glossary/gas-fee): The cost of getting your transaction included on the blockchain. Goes to the people who run the network.
- [Genesis Block](https://fudfomo.co/glossary/genesis-block): The very first block of a blockchain.
- [Governance Token](https://fudfomo.co/glossary/governance-token): A token that gives you the right to vote on changes to a crypto project, usually a DAO.
- [Halving](https://fudfomo.co/glossary/halving): An event where the reward for mining new Bitcoin blocks is cut in half. Happens roughly every four years.
- [Hard Fork](https://fudfomo.co/glossary/hard-fork): A blockchain rule change that is not backwards compatible. Old software cannot follow the new chain.
- [Hash](https://fudfomo.co/glossary/hash): A short fingerprint of any piece of data, produced by a one-way mathematical function.
- [Hash Rate](https://fudfomo.co/glossary/hash-rate): How much total computing power is securing a proof-of-work network like Bitcoin.
- [Honeypot](https://fudfomo.co/glossary/honeypot): A token or contract designed to lure buyers in and then prevent them from selling.
- [Hot Wallet](https://fudfomo.co/glossary/hot-wallet): A wallet connected to the internet, like a phone app. Convenient for everyday use, less safe for big balances.
- [Howey Test](https://fudfomo.co/glossary/howey-test): A US legal test for deciding whether something counts as an investment contract, and so a security.
- [ICO](https://fudfomo.co/glossary/ico): Initial coin offering. An early sale where a project raises money by selling its new token.
- [Immutable](https://fudfomo.co/glossary/immutable): Cannot be changed once recorded. The standard property of confirmed blockchain history.
- [Impermanent Loss](https://fudfomo.co/glossary/impermanent-loss): A paper loss that liquidity providers see when the prices of their pooled tokens move apart.
- [KYC](https://fudfomo.co/glossary/kyc): Know Your Customer. The identity checks an exchange runs before letting you trade.
- [Layer 1](https://fudfomo.co/glossary/layer-1): The base blockchain itself, like Bitcoin or Ethereum. The foundation everything else builds on.
- [Layer 2](https://fudfomo.co/glossary/layer-2): A faster, cheaper network built on top of a layer 1 like Ethereum. Borrows the main chain's security.
- [Lending Protocol](https://fudfomo.co/glossary/lending-protocol): A DeFi app that lets users deposit crypto to earn interest and others borrow against collateral.
- [Leverage](https://fudfomo.co/glossary/leverage): Trading with borrowed funds, so a small move in the price has a much bigger effect on your position.
- [Lightning Network](https://fudfomo.co/glossary/lightning-network): A layer 2 for Bitcoin that lets users send fast, cheap payments through a network of payment channels.
- [Liquid Staking](https://fudfomo.co/glossary/liquid-staking): Staking your coins through a service that gives you a tradable token in return.
- [Liquidation](https://fudfomo.co/glossary/liquidation): When a borrower's collateral is sold off automatically because their loan has fallen below the safety threshold.
- [Liquidity Pool](https://fudfomo.co/glossary/liquidity-pool): A shared pot of two tokens that lets people trade between them on a decentralised exchange.
- [Long](https://fudfomo.co/glossary/long): A position that profits when the price goes up.
- [LP Token](https://fudfomo.co/glossary/lp-token): A receipt token you get for depositing into a liquidity pool. It tracks your share of the pool.
- [Margin](https://fudfomo.co/glossary/margin): The capital you put up to open and maintain a leveraged position.
- [Market Cap](https://fudfomo.co/glossary/market-cap): The current price of a coin multiplied by how many are in circulation. A rough size measure.
- [Market Maker](https://fudfomo.co/glossary/market-maker): A participant who quotes both buy and sell prices, providing liquidity in exchange for a small spread.
- [Memecoin](https://fudfomo.co/glossary/memecoin): A token whose value comes mostly from internet culture rather than any underlying product.
- [Mempool](https://fudfomo.co/glossary/mempool): The waiting area where pending transactions sit before they are included in a block.
- [Merkle Tree](https://fudfomo.co/glossary/merkle-tree): A way of summarising many pieces of data into a single hash, used to prove a single piece of data is in the set.
- [MEV](https://fudfomo.co/glossary/mev): Extra profit that validators or specialised bots can earn by reordering or inserting transactions in a block.
- [MiCA](https://fudfomo.co/glossary/mica): The Markets in Crypto-Assets regulation. The European Union's main rulebook for crypto firms.
- [Mining](https://fudfomo.co/glossary/mining): Using computers to add new transactions to a blockchain and earn newly created coins as a reward.
- [Modular Blockchain](https://fudfomo.co/glossary/modular-blockchain): A blockchain design that splits responsibilities across separate, specialised layers.
- [Money Market](https://fudfomo.co/glossary/money-market): A market for short-term borrowing and lending of low-risk assets. In crypto, often a stablecoin lending pool.
- [Multi-sig](https://fudfomo.co/glossary/multi-sig): A wallet that needs more than one signature to move funds. Common for companies and treasuries.
- [NFT](https://fudfomo.co/glossary/nft): A token that represents ownership of a unique item, like a piece of digital art or a ticket.
- [Node](https://fudfomo.co/glossary/node): A computer that helps run a blockchain by storing the ledger and checking new transactions.
- [Nonce](https://fudfomo.co/glossary/nonce): A number used once. In mining it is the value miners search for; in transactions it stops the same one being processed twice.
- [Open Interest](https://fudfomo.co/glossary/open-interest): The total value of outstanding derivatives contracts at a given moment.
- [Optimistic Rollup](https://fudfomo.co/glossary/optimistic-rollup): A type of layer 2 that assumes batches are valid by default and lets anyone challenge them.
- [Options](https://fudfomo.co/glossary/options): A contract that gives the buyer the right, but not the obligation, to buy or sell at a set price by a set date.
- [Oracle](https://fudfomo.co/glossary/oracle): A service that brings outside information, like prices or sports scores, onto a blockchain.
- [Order Book](https://fudfomo.co/glossary/order-book): A live list of buy and sell orders at different prices on an exchange.
- [OTC Desk](https://fudfomo.co/glossary/otc-desk): An over-the-counter trading desk that matches large crypto buyers and sellers off the public exchanges.
- [Permissionless](https://fudfomo.co/glossary/permissionless): A property of a system where anyone can use it or join without asking permission.
- [Perpetual Futures](https://fudfomo.co/glossary/perpetual-futures): A futures contract with no expiry date. Common in crypto, kept in line with the spot price by funding payments.
- [Phishing](https://fudfomo.co/glossary/phishing): A scam where attackers impersonate a trusted service to steal credentials or trick you into signing a bad transaction.
- [Pig Butchering](https://fudfomo.co/glossary/pig-butchering): A long-running scam that builds a fake personal relationship before steering the victim into fraudulent crypto investments.
- [Private Key](https://fudfomo.co/glossary/private-key): A secret string of characters that proves you own a crypto address. Anyone who sees it can spend your funds.
- [Proof of Stake](https://fudfomo.co/glossary/proof-of-stake): A way to secure a blockchain using locked-up coins instead of computing power. Used by Ethereum.
- [Proof of Work](https://fudfomo.co/glossary/proof-of-work): A way to secure a blockchain by making computers do a lot of calculation. Used by Bitcoin.
- [Pseudonymous](https://fudfomo.co/glossary/pseudonymous): Identified by an address rather than a real name, but still trackable on chain.
- [Public Key](https://fudfomo.co/glossary/public-key): An address-like value that other people use to send you crypto. Safe to share.
- [Pump and Dump](https://fudfomo.co/glossary/pump-and-dump): A market manipulation where insiders inflate the price of a token, then sell into the buying frenzy.
- [Reentrancy](https://fudfomo.co/glossary/reentrancy): A smart contract bug that lets an attacker call back into a contract before its first call finishes, draining funds.
- [Restaking](https://fudfomo.co/glossary/restaking): Reusing already-staked coins as security for additional services, usually for extra yield.
- [Rollup](https://fudfomo.co/glossary/rollup): A type of layer 2 that bundles many transactions together and writes a summary back to the main chain.
- [Rug Pull](https://fudfomo.co/glossary/rug-pull): A scam where the creators of a token suddenly drain liquidity or sell their stash, leaving holders with worthless tokens.
- [Sanctions Screening](https://fudfomo.co/glossary/sanctions-screening): Checking that the people and addresses involved in a transaction are not on a sanctions list.
- [Sandwich Attack](https://fudfomo.co/glossary/sandwich-attack): A specific MEV trade where a bot places one order before and one after your trade to extract value.
- [SEC](https://fudfomo.co/glossary/sec): The US Securities and Exchange Commission. The American regulator that decides whether a token counts as a security.
- [Securities](https://fudfomo.co/glossary/securities): A regulated category of financial instrument, like shares or bonds. Tokens that meet the test are subject to strict rules.
- [Seed Phrase](https://fudfomo.co/glossary/seed-phrase): A list of 12 or 24 ordinary words that backs up an entire wallet.
- [Sequencer](https://fudfomo.co/glossary/sequencer): The operator that orders transactions on a layer 2 before they are posted to the main chain.
- [Short](https://fudfomo.co/glossary/short): A position that profits when the price goes down.
- [Sidechain](https://fudfomo.co/glossary/sidechain): A separate blockchain that runs alongside a main chain and is connected by a bridge.
- [SIM Swap](https://fudfomo.co/glossary/sim-swap): An attack where a scammer takes over your phone number to bypass two-factor authentication and break into accounts.
- [Slashing](https://fudfomo.co/glossary/slashing): When part of a validator's stake is destroyed as a penalty for breaking the rules.
- [Slippage](https://fudfomo.co/glossary/slippage): The gap between the price you expected when you placed a trade and the price you actually got.
- [Smart Contract](https://fudfomo.co/glossary/smart-contract): A program that runs on a blockchain and does what it says, automatically.
- [Soft Fork](https://fudfomo.co/glossary/soft-fork): A blockchain rule change that is backwards compatible. Old software still works, just with fewer features.
- [Solidity](https://fudfomo.co/glossary/solidity): The most common programming language for writing smart contracts on Ethereum.
- [Spot Market](https://fudfomo.co/glossary/spot-market): A market for buying and selling crypto for immediate delivery, at the current price.
- [Stablecoin](https://fudfomo.co/glossary/stablecoin): A token designed to hold the same value as a regular currency, usually the US dollar.
- [Staking](https://fudfomo.co/glossary/staking): Locking up your crypto to help run a blockchain. In return, you earn rewards, similar to interest.
- [State Channel](https://fudfomo.co/glossary/state-channel): A way for two or more users to transact off-chain and only settle the final balance on the main chain.
- [Sybil Attack](https://fudfomo.co/glossary/sybil-attack): An attack where one party controls many fake identities to gain influence.
- [Tax Lot](https://fudfomo.co/glossary/tax-lot): A specific batch of crypto bought at a known price and date, used to calculate gains on disposal.
- [Token](https://fudfomo.co/glossary/token): A unit of value created on top of an existing blockchain like Ethereum.
- [Tokenomics](https://fudfomo.co/glossary/tokenomics): The economic design of a token: total supply, how it is distributed, and how it changes over time.
- [Total Supply](https://fudfomo.co/glossary/total-supply): The maximum number of coins or tokens that will ever exist for a project.
- [Transaction](https://fudfomo.co/glossary/transaction): An instruction recorded on a blockchain that moves value or runs a smart contract.
- [Travel Rule](https://fudfomo.co/glossary/travel-rule): A regulation that requires crypto firms to share sender and recipient information when transferring above a threshold.
- [Trustless](https://fudfomo.co/glossary/trustless): A system where users do not need to trust each other or a central party for it to work as expected.
- [TVL](https://fudfomo.co/glossary/tvl): Total value locked. The dollar value of all assets sitting inside a DeFi protocol or chain.
- [Validator](https://fudfomo.co/glossary/validator): A participant in a proof-of-stake network who proposes and confirms new blocks. Earns rewards and can be slashed.
- [Validity Proof](https://fudfomo.co/glossary/validity-proof): A cryptographic proof that a batch of transactions on a ZK-rollup followed all the rules.
- [VASP](https://fudfomo.co/glossary/vasp): Virtual Asset Service Provider. A FATF term for any business that handles crypto on behalf of customers.
- [Vault](https://fudfomo.co/glossary/vault): A DeFi smart contract that automates a strategy on behalf of depositors.
- [Vesting](https://fudfomo.co/glossary/vesting): A schedule that releases tokens to founders, investors, or staff gradually over time.
- [Wallet](https://fudfomo.co/glossary/wallet): An app or device that holds the keys you need to spend and receive crypto.
- [Wash Trading](https://fudfomo.co/glossary/wash-trading): Buying and selling the same asset between connected accounts to fake trading volume.
- [Web3](https://fudfomo.co/glossary/web3): A loose label for the part of the internet built on blockchains, wallets, and tokens.
- [Whale](https://fudfomo.co/glossary/whale): A person or entity that holds a very large amount of a coin or token, big enough to move the market.
- [Whitepaper](https://fudfomo.co/glossary/whitepaper): A document that explains how a crypto project works and why it should exist.
- [Wrapped Token](https://fudfomo.co/glossary/wrapped-token): A token on one blockchain that represents a coin from another. Lets you use Bitcoin on Ethereum, for example.
- [Yield Farming](https://fudfomo.co/glossary/yield-farming): Moving crypto between DeFi apps to earn the highest rewards. Higher yields usually mean higher risk.
- [ZK-Rollup](https://fudfomo.co/glossary/zk-rollup): A layer 2 that posts cryptographic proofs back to the main chain to show its batches are valid.

## See the full catalogue

What The Block! provides 2,000+ plain-English crypto definitions, available as embeddable hover-state tooltips for crypto exchanges. https://wtb.fudfomo.co