transfer(address to, uint tokens) public returns (bool success)
Transfer the balance from owner's account to another account
transferFrom(address from, address to, uint tokens) public returns (bool success)
tokens amount of tokens from address
from to address
The transferFrom method is used for a withdraw workflow, allowing contracts to send tokens on your behalf, for example to "deposit" to a contract address and/or to charge
fees in sub-currencies; the command should fail unless the _from account has deliberately authorized the sender of the message via some mechanism; we propose these standardized APIs for approval.
approve(address spender, uint tokens) public returns (bool success)
spender to withdraw from your account, multiple times, up to the
If this function is called again it overwrites the current allowance with _value.