USDC & Stablecoin Glossary
Plain-English definitions of every term you need to understand USDC, stablecoins, and the crypto ecosystem.
Address (Wallet Address)
A unique string of characters that identifies where cryptocurrency can be sent, like an account number for your wallet.
Algorithmic Stablecoin
A stablecoin that maintains its peg through automated smart contract mechanisms rather than holding real-world reserves.
AML (Anti-Money Laundering)
Laws and procedures designed to prevent criminals from disguising illegally obtained funds as legitimate income.
AMM (Automated Market Maker)
A smart contract that enables trading by using a mathematical formula to set prices based on the ratio of tokens in a liquidity pool.
APR (Annual Percentage Rate)
The yearly interest rate on a deposit or loan, without accounting for compounding.
APY (Annual Percentage Yield)
The total return on a deposit over one year, including compound interest.
Attestation
An independent third-party examination that verifies USDC reserves meet or exceed the amount of USDC in circulation.
Block Explorer
A website that lets you look up transactions, addresses, and other data on a blockchain.
Block Time
The average time it takes for a new block to be added to a blockchain, determining how quickly transactions are processed.
Blockchain
A distributed, immutable digital ledger that records transactions across a network of computers.
Bridging
Moving cryptocurrency from one blockchain to another. For example, moving USDC from Ethereum to Base.
Burn
Permanently destroying cryptocurrency tokens, removing them from circulation forever.
Capital Gains
The profit you make when you sell or exchange a cryptocurrency for more than you paid for it.
CCTP (Cross-Chain Transfer Protocol)
A protocol that enables native USDC transfers between blockchains by burning tokens on one chain and minting them on another.
CEX (Centralized Exchange)
A cryptocurrency exchange run by a company that holds your funds and matches buy/sell orders. Examples: Coinbase, Kraken, Binance.
Chargeback
A reversal of a payment, typically initiated by a credit card holder disputing a transaction with their bank.
Circulating Supply
The total number of tokens currently in circulation and available on the market.
Cold Storage
Keeping cryptocurrency keys completely offline, disconnected from the internet, for maximum security.
Collateral
Assets pledged as security for a loan. In DeFi, you deposit crypto collateral to borrow other assets.
Confirmation
The number of new blocks added to the blockchain after your transaction's block, indicating how settled the transaction is.
Cost Basis
The original price you paid for a cryptocurrency, used to calculate capital gains or losses when you sell.
Custodial Wallet
A wallet where a third party (like an exchange) holds your private keys on your behalf.
DeFi (Decentralized Finance)
Financial services built on blockchain smart contracts that operate without traditional intermediaries like banks.
Depeg
When a stablecoin's market price drops significantly below (or rises above) its target peg, typically $1.00.
DEX (Decentralized Exchange)
A cryptocurrency exchange that operates through smart contracts, allowing users to trade directly without an intermediary.
ERC-20
A technical standard for fungible tokens on Ethereum and compatible blockchains. USDC is an ERC-20 token.
Escrow
A service that holds funds on behalf of two parties until the terms of a transaction are met.
Fiat Currency
Government-issued money like the U.S. dollar, euro, or yen that isn't backed by a physical commodity.
Fiat-Backed Stablecoin
A stablecoin backed by real-world assets like cash and government bonds, held in reserve by the issuer.
Finality
The point at which a blockchain transaction becomes irreversible and can never be changed or rolled back.
Flash Loan
An uncollateralized loan that must be borrowed and repaid within a single blockchain transaction.
Freeze (Blacklist)
The ability to block specific addresses from sending or receiving USDC, used for sanctions compliance and law enforcement.
Gas Fees
Transaction fees paid to blockchain validators for processing and confirming transactions.
GENIUS Act
Proposed U.S. legislation to create a federal regulatory framework for stablecoin issuers.
Governance Token
A token that gives holders voting rights on decisions about a DeFi protocol's development and rules.
Hardware Wallet
A physical device that stores cryptocurrency private keys offline. The most popular form of cold storage.
Hot Wallet
A cryptocurrency wallet connected to the internet, offering convenience but more exposure to potential hacks.
Impermanent Loss
The potential loss a liquidity provider faces when the price ratio of pooled tokens changes compared to simply holding them.
KYC (Know Your Customer)
Identity verification requirements that financial services must perform to prevent fraud and money laundering.
Layer 1 (L1)
The base blockchain network that processes and finalizes transactions on its own. Examples: Ethereum, Solana, Avalanche.
Layer 2 (L2)
A secondary network built on top of a Layer 1 blockchain to increase speed and reduce transaction costs. Examples: Base, Arbitrum, Optimism.
Lending Protocol
A DeFi application that lets users lend crypto to earn interest and borrow crypto against collateral.
Liquidation
The forced sale of collateral when a borrower's collateral value drops below the required minimum ratio.
Liquidity
How easily an asset can be bought or sold without significantly affecting its price.
Liquidity Pool
A smart contract holding paired tokens (like USDC/ETH) that enables trading on a decentralized exchange.
Liquidity Provider (LP)
A person or entity that deposits tokens into a liquidity pool on a decentralized exchange, earning trading fees in return.
Mainnet
The live, production version of a blockchain where real transactions with real value occur.
Market Cap (Market Capitalization)
The total value of a cryptocurrency, calculated by multiplying the price per token by the circulating supply.
MiCA (Markets in Crypto-Assets)
The European Union's regulatory framework for cryptocurrency, including specific rules for stablecoin issuers.
Micropayment
A very small financial transaction, typically under $1, that's impractical with traditional payment processors.
Mint
The process of creating new stablecoin tokens by depositing an equivalent amount of fiat currency.
Multisig (Multi-Signature)
A wallet that requires multiple private keys to authorize a transaction, adding an extra layer of security.
Native Token
A token issued directly on a blockchain by its official issuer, as opposed to a bridged or wrapped version.
Network (Blockchain Network)
A specific blockchain system where transactions are processed. When sending USDC, you must choose which network to use.
Offramp
A service that lets you convert cryptocurrency back into traditional money (fiat).
Onramp
A service that lets you convert traditional money (fiat) into cryptocurrency.
Oracle
A service that feeds real-world data (like asset prices) to blockchain smart contracts, which can't access external information on their own.
P2P (Peer-to-Peer)
Direct transactions between individuals without an intermediary, used for buying, selling, or transferring crypto.
Peg
The target price a stablecoin is designed to maintain, typically $1.00 for dollar-pegged stablecoins.
Phishing
A scam where attackers impersonate legitimate services to trick you into revealing passwords, seed phrases, or approving malicious transactions.
Private Key
A secret cryptographic code that proves ownership of a blockchain address and authorizes transactions.
Proof of Stake (PoS)
A consensus mechanism where validators stake cryptocurrency as collateral to earn the right to verify transactions.
Redeem
The process of exchanging stablecoin tokens for their underlying fiat currency value, effectively burning the tokens.
Remittance
Money sent from one country to another, typically by a foreign worker sending funds to family back home.
Reserves
The pool of real-world assets (U.S. Treasuries, cash) held to back each USDC token at a 1:1 ratio.
Rollup
A Layer 2 scaling solution that bundles many transactions together and submits them to the main chain as a single batch.
Sanctions
Government restrictions that prohibit financial transactions with specific individuals, organizations, or countries.
Seed Phrase (Recovery Phrase)
A set of 12 or 24 words that can restore your crypto wallet and all its private keys. Also called a recovery phrase or mnemonic.
Self-Custody
Holding your own private keys, giving you full control over your cryptocurrency without relying on a third party.
Settlement
The final, irreversible transfer of an asset from one party to another. On blockchains, settlement happens when a transaction is confirmed.
Slippage
The difference between the expected price of a trade and the actual price you receive when the trade executes.
Smart Contract
Self-executing code deployed on a blockchain that automatically enforces the terms of an agreement.
Smart Contract Audit
A security review of a smart contract's code by independent experts to identify vulnerabilities before or after deployment.
Stablecoin
A cryptocurrency designed to maintain a stable value, usually pegged 1:1 to a fiat currency like the U.S. dollar.
Staking
Locking up cryptocurrency to help secure a blockchain network, earning rewards in return.
Swap
Exchanging one cryptocurrency for another, typically done through a DEX or exchange.
Taxable Event
Any crypto transaction that triggers a tax obligation, including selling, swapping, or spending cryptocurrency.
Testnet
A test version of a blockchain used by developers to experiment without risking real money.
Token
A digital asset created on an existing blockchain. USDC is a token that runs on multiple blockchains.
Transaction Hash (Tx Hash)
A unique identifier assigned to every blockchain transaction, used to look up and verify the transaction.
TVL (Total Value Locked)
The total value of cryptocurrency deposited in a DeFi protocol or across an entire blockchain.
Two-Factor Authentication (2FA)
A security method requiring two different forms of verification to access an account, like a password plus a code from your phone.
U.S. Treasury Securities
Debt instruments issued by the U.S. government, considered the safest financial assets in the world. They back the majority of USDC reserves.
USDC (USD Coin)
A regulated, fully-backed stablecoin pegged to the U.S. dollar. Each USDC is redeemable for $1.
Validator
A computer that verifies transactions and adds new blocks to a proof-of-stake blockchain.
Wallet
Software or hardware that stores your private keys and lets you send, receive, and manage cryptocurrency.
Wrapped Token
A token on one blockchain that represents an asset from another blockchain, created through a bridge.
x402
A payment protocol that uses the HTTP 402 status code to enable machine-to-machine payments with USDC.
Yield
The return earned on deposited or lent cryptocurrency, expressed as an interest rate.
This glossary is provided for educational purposes. USDC.org is an independent resource and is not affiliated with Circle Internet Financial. Definitions are simplified for accessibility and may not cover every technical nuance.