State Variables and Storage Layout

Welcome to understanding how data lives on the blockchain! In Solidity, state variables are special variables whose values are permanently stored in the contract's storage on the blockchain.

Think of them as the persistent memory of your smart contract. Their values are saved even after a function finishes executing and across different transactions.

Solidity uses different data locations to manage where information is stored during contract execution. These locations have big impacts on gas costs and how your variables behave.

• storage: Permanent state on the blockchain.
• memory: Temporary data for function execution.
• calldata: Read-only data for external function arguments.