What Is the Difference between a Receive and a Fallback Function in Solidity?
The receive function is specifically executed when a transaction sends Ether to the contract with no data (empty calldata ). It must be declared as payable and cannot have arguments.
The fallback function is executed when a contract is called without matching any other function, or if it receives Ether with data. Both can be entry points for a reentrancy attack, but receive is specifically for plain Ether transfers.
Glossar
Receive Function
Handler ⎊ The receive function is a specialized external function in Solidity, introduced to explicitly handle plain Ether transfers sent to a contract without any accompanying calldata.
Fallback Function
Contingency ⎊ A fallback function within cryptocurrency derivatives serves as a pre-defined operational protocol activated when primary system components, such as oracles or clearinghouses, experience disruptions or fail to deliver expected data or execution.
Calldata
Data ⎊ Calldata refers to the immutable region of memory used to store input arguments for external function calls in Ethereum transactions and internal contract messages, remaining accessible throughout the execution lifecycle.