What is Bitcoin Cash?
Bitcoin Cash is peer-to-peer electronic cash for the Internet. It is fully decentralized, with no central bank and requires no trusted third parties to operate.
Is Bitcoin Cash different from 'Bitcoin'?
Yes. Bitcoin Cash is the continuation of the Bitcoin project as peer-to-peer digital cash. It is a fork of the Bitcoin blockchain ledger, with upgraded consensus rules that allow it to grow and scale.
If I own Bitcoin, do I automatically own Bitcoin Cash too?
Anyone who held Bitcoin at the time Bitcoin Cash was created became owners of Bitcoin Cash. This means that Bitcoin holders as of block 478558 (August 1st, 2017 about 13:16 UTC) have the same amount of Bitcoin Cash as they had Bitcoin at that time. If your Bitcoins are stored by a third party such as an exchange, then you must inquire with them about your Bitcoin Cash.
Any transactions after the August 1st ledger split are completely separate between Bitcoin and Bitcoin Cash. This means any Bitcoin acquired after the split does not include any Bitcoin Cash, and any Bitcoin Cash does not include any Bitcoin.
How is transaction replay being handled between the new and the old blockchain?
Bitcoin Cash transactions use a new signature hashing algorithm indicated by the flag SIGHASH_FORKID. These signatures are not valid on the Bitcoin Legacy network. This prevents Bitcoin Cash transactions from being replayed on the Bitcoin blockchain and vice versa.