Glossary

The terms used across this site, in plain English

Every blockchain-specific term used elsewhere on this site gets a one-line, plain-English definition here. A reference, not required reading.

Audit trail: The permanent, timestamped record of every action a contract has taken.
Blockchain: A shared record of transactions duplicated across many independent computers, making it very hard for one party to alter history unnoticed.
Escrow: Funds held by the contract itself rather than either party, released only once agreed conditions are met.
Ethereum: The blockchain network this demo is built on. A shared, public computer that many independent parties run copies of.
Gas: The fee paid to the network to process a transaction. Think of it as postage for every action a contract takes; the cost varies with network congestion.
Layer 2: A secondary network built on top of Ethereum that processes transactions more cheaply and settles back to it, for example Arbitrum or Base.
Mainnet: The live, production Ethereum network where real value moves.
Multi-sig (multi-signature): A wallet that requires more than one key to approve an action, so no single person can move funds alone.
Node: A single computer running a copy of the network. The more independent nodes there are, the harder the network is to tamper with.
On-chain / off-chain: On-chain means recorded permanently on the blockchain. Off-chain means it lives in a traditional system instead.
Oracle: A trusted service that feeds real-world data, like a delivery confirmation, onto the blockchain, since a smart contract can't see outside itself.
Private key (signing key): The credential that proves control of a wallet. Whoever holds it can act on the wallet's behalf, so losing it or having it stolen is the crypto equivalent of losing the only signed copy of a check.
RPC (Remote Procedure Call): The technical connection point applications use to read from, or send transactions to, the network.
Smart contract: Self-executing code deployed to a blockchain that runs exactly as written, with no ability for a human to quietly change the outcome after the fact.
Smart contract audit: An independent security review of a contract's code before it is trusted with real funds.
Solidity: The programming language most Ethereum smart contracts are written in.
Stablecoin: A digital token designed to hold a stable value, usually pegged 1:1 to a currency like the US dollar, for example USDC.
Testnet: A practice version of the network, functionally identical to mainnet, where nothing of real value is at stake.
Wallet: An account on the network, controlled by a private key, that can hold funds or trigger a contract's functions.