What is a backend?
You can think of a backend as a target platform for your smart contract.
OdraVM
The OdraVM is a simple implementation of a mock backend with a minimal set of features that allows testing
Casper
The Casper backend allows you to compile your contracts into WASM files which can be deployed
Livenet
The Livenet backend lets us deploy and test the contracts on the real blockchain. It can be a local