What is Mainnet?
Mainnet is the primary production blockchain network where real transactions with real economic value occur — as opposed to testnets which use valueless tokens for development.
WHY IT MATTERS
Mainnet is where it counts — live blockchain with real money, users, and consequences. When a protocol 'launches on mainnet,' smart contracts are deployed with actual tokens and financial risk.
The distinction matters for development workflow. Build on testnets, audit contracts, deploy to mainnet. Bugs on testnet cost nothing; bugs on mainnet can cost millions.
Some protocols run 'mainnet beta' periods — deployed with real funds but with safety measures like deposit caps and emergency pause functions.