I have several questions all revolving around one core concept: how an Ethereum account relates to a given coin (blockchain). For example, if I have an account I made to mine ETH, how does it know that the Ether on my account is ETH and not say ETC or any other Ethash based coin? I don't recall anything in the setup process where I told it which coin I wanted to mine, it just seemed to presume ETH. Say I wanted to branch out and mine some ETC and maybe Musicoin. Would I need a separate account for each of these? Or is it that each blockchain keeps my address in its own ledger? My question then would be that if I query my account balance in geth, which blockchain is it going to look up on? I can't seem to find any solid answers to this on Google, so any help would be greatly appreciated!
ETC has the same network_id = 1 as ETH.
ETC and ETH have different sets of bootnodes predefined in their clients. This results in two non-overlapping networks. (You can obviously change the bootnodes).
To distinguish ETH and ETC transactions
chain_id was introduced in EIP-155.
chain_id is mixed into transaction signature to prevent replay attacks.
So, if ETH node somehow connects to ETC peer it will get block or transaction that does not belong to its network but it will consider those as invalid and will drop the connection to that peer.