Function can send ETH without using payable?

Question

I understand that a function must be declared as payable in order to send ETH to some address.

I am trying this piece of code using Solidity 0.7.1

pragma solidity ^0.7.1;

contract SendMoney {

uint public balanceReceived; 

function sendETHToSmartContract() public payable {
    balanceReceived += msg.value;
}   

function getBalance() public view returns(uint){
    return address(this).balance;
}

function sendETHOutToCaller() public {
    msg.sender.transfer(getBalance());   
}
}

I declared function sendETHOutToCaller() without payable. When I run it , I can call function sendETHOutToCaller() to transfer the ETH from smart contract to the caller. Works fine on Solidity 0.7

Why in this case I am able to transfer the ETH from smart contract to the caller without payable ?

Answer 1

Keyword payable in the function is needed to make the function able to receive ether. Sending ether is possible from any function, as long as the address sending is payable.