What's the least amount of ether that can be sent in a transaction? Would it be 0.000000000000000001? Or can you send 0 ether? How would you do that?
You can send zero Ethereum in a transaction (in fact, many of the function calls you make on smart contracts will have you sending zero Ethereum), but you aren't currently able to spend zero Ethereum when you send a transaction. At the very least, you will have to spend the cost of gas to pay for the transaction's processing.
The send is specified in the
amount field of a transaction. Your Ethereum wallet will allow you to enter this amount if the smart contract requires it, or if you are sending ether to another person. The
value can be zero, for example, if you are simply sending your friend a message in the
input field. But you would get charged
gas which you can think of as a transaction fee. The wallet will extract the gas and send it along by default.
Hope that helps.