When a single entity controls a majority of a proof-of-work network's hash rate and can double-spend or censor transactions.

A string derived from a public key used to send and receive crypto on a blockchain.

Free distribution of tokens to wallets, usually to bootstrap a network or reward early users.

Any cryptocurrency other than Bitcoin.

Automated Market Maker. A DEX design that prices assets using a formula and liquidity pools instead of an order book.

Annualized yield. APR is simple; APY compounds. Common in DeFi lending and staking.

All-Time High / All-Time Low price of an asset.

Slang for the collection of tokens a person holds.

1/100th of a percent. 25 bps = 0.25%.

A prolonged downtrend, typically 20%+ off highs with negative sentiment.

A batch of transactions cryptographically linked to the previous block.

An append-only ledger of blocks replicated across many independent nodes.

New coins issued to the miner or validator that produces a block.

Software that moves assets or messages between blockchains. Historically the highest-risk DeFi surface.

A sustained uptrend with rising prices and optimistic sentiment.

Permanently removing tokens from circulation by sending them to an unspendable address.

Centralized Exchange. A custodial venue like Coinbase, Binance, or Kraken.

Keeping keys fully offline — hardware wallets, paper, or air-gapped machines.

The mechanism that gets independent nodes to agree on the ledger state.

Who controls the private keys. 'Not your keys, not your coins.'

Decentralized Autonomous Organization. On-chain governance over a protocol treasury or parameters.

Decentralized application — a frontend that talks to on-chain smart contracts.

Decentralized Finance. Lending, trading, and derivatives built on smart contracts, without custodians.

Decentralized Exchange. Non-custodial trading via smart contracts (e.g. Uniswap).

A trivial amount of crypto too small to move economically after fees.

Ethereum Improvement Proposal. The formal process for evolving the protocol.

The Ethereum standard for fungible tokens.

Ethereum standards for NFTs (unique / semi-fungible tokens).

Ethereum Virtual Machine. The runtime that executes smart contracts.

Government-issued currency like USD or EUR.

A change to protocol rules. Soft forks are backwards compatible; hard forks are not.

The fee paid to execute a transaction, measured in gwei on Ethereum.

The first block in a blockchain.

The Bitcoin event, every ~4 years, that cuts the block reward in half.

A fixed-length fingerprint of data. Foundation of blockchain integrity.

Total computational power securing a proof-of-work network.

Long-term holding through volatility. Originally a typo of 'hold'.

A wallet with keys on an internet-connected device. Convenient, more exposed.

Initial token offerings on centralized, decentralized, or exchange-launchpad venues.

The opportunity cost an LP takes when pool prices diverge from just holding the assets.

Know Your Customer. Identity verification required by regulated exchanges.

A base blockchain like Bitcoin, Ethereum, or Solana.

A protocol built on top of an L1 that scales throughput (e.g. Arbitrum, Optimism, Base).

Forced closure of a leveraged position when collateral falls below margin requirements.

A smart-contract-held reserve of two or more assets that traders swap against.

Liquidity Provider. Deposits assets into a pool in exchange for fees.

The live production blockchain. Testnets are for development.

Price × circulating supply. A rough proxy for network size.

A hash tree that lets you prove a transaction is in a block without downloading the whole block.

The pool of unconfirmed transactions waiting to be included in a block.

Maximal Extractable Value. Profit validators can capture by reordering, inserting, or censoring txs.

Producing blocks in a proof-of-work chain by solving cryptographic puzzles.

A wallet that requires M-of-N signatures to spend. Standard for treasuries.

Non-Fungible Token. A unique on-chain asset (art, collectibles, credentials).

A computer running a blockchain client, validating and relaying transactions.

A number used once — either the miner's PoW guess or an account's transaction counter.

A service that brings off-chain data (prices, events) into smart contracts.

A valid block that lost the race and is not part of the canonical chain.

Proof-of-Stake. Consensus where validators lock capital and lose it if they misbehave.

Proof-of-Work. Consensus where miners burn energy to produce blocks.

The secret that authorizes spending from an address. Guard it like a password.

Derived from the private key; used to verify signatures. Addresses come from public keys.

A scam where founders drain liquidity or abandon a project after taking user funds.

12-24 words that back up a wallet. Anyone with them owns the wallet — never share.

Splitting a blockchain into parallel pieces to scale throughput.

A penalty in PoS that burns a validator's stake for misbehavior.

The difference between expected and executed trade price, usually from thin liquidity.

Code deployed on a blockchain that runs deterministically when called.

The dominant programming language for Ethereum smart contracts.

A token pegged to a stable asset, usually USD. Fiat-backed, crypto-collateralized, or algorithmic.

Locking tokens to help secure a PoS network in exchange for rewards.

A parallel network for development where tokens have no real value.

Transactions per second. A rough throughput metric.

Traditional Finance — banks, brokers, exchanges outside of crypto.

Total Value Locked. Dollar value of assets deposited in a protocol.

A node that proposes and attests to blocks in a PoS network.

A schedule that gradually unlocks team or investor tokens over time.

Software or hardware that stores keys and signs transactions.

Denominations of ETH. 1 ETH = 10^18 wei. 1 gwei = 10^9 wei.

An address large enough to move markets when it trades.

The document describing a protocol's design, economics, and rationale.

Chasing the highest DeFi returns by rotating capital between protocols.

A cryptographic proof that a statement is true without revealing why. Basis of zk-rollups and privacy chains.

An L2 that batches transactions and posts a validity proof to the L1.