approve fn

The approve function is used to enable the user to approve the transfer (once the owner allows for that transfer first).

function transferFrom(address _from, address _to, uint256 _tokenId) external payable;

function approve(address _approved, uint256 _tokenId) external payable;`

The token's owner first calls approve with the address he wants to transfer to, and the _tokenID . The contract then stores who is approved to take a token, usually in a mapping (uint256 => address).

Then, when the owner or the approved address calls transferFrom, the contract checks if that msg.sender is the owner or is approved by the owner to take the token, and if so it transfers the token to him.

In the transferFrom only case the sender of the token calls the transferFrom function; in this case the owner or the approved receiver of the token calls it.

[!question] Best way for airdropping?