Difference between address(token).transfer and token.transfer

We know that every token implements IERC20 has the transfer function. And every account in ethereum also has the transfer function.

As a ERC20 contract, we can call the transfer function in the smart contract like this token.transfer(msg.sender,amount). As a ERC20 account we call the transfer function like this address(this).transfer(amount).

But be aware that these two line codes are very different. token.transfer(msg.sender,amount) is to transfer the ERC20 token from the contract to the msg.sender.

And address(token).transfer(amount) is using to transfer ethereum coins from the contract to the token account. If the