After placing an ink! smart contract on canvas-node using https://paritytech.github.io/canvas-ui, what does the created code hash represent and what is it used for?
This is used to identify the WASM stored on chain, and as hashmap to retrieve it from storage. Commonly this is used to instantiate a new instance of the contract: https://paritytech.github.io/ink-docs/getting-started/deploy-your-contract