Definition
A test version of a blockchain network used by developers to test applications and protocols without risking real money. Testnet tokens have no monetary value.
Why It Matters
Testnets allow developers to experiment and test without consequences. As a user, knowing whether you're on mainnet or testnet prevents accidental loss of real funds.
Example
A DeFi developer tests their new lending protocol on Ethereum's Sepolia testnet for months before launching on mainnet with real user funds.
Related Terms
Mainnet
Blockchain
Smart Contract
Node