Bitcoin Cash is a split from Bitcoin with a protocol upgrade to fix on-chain capacity. If Bitcoin Cash gets majority of Proof-of-Work then it becomes de facto Bitcoin. It will be a Bitcoin without Segregated Witness (SegWit) as soft fork, where upgrades of the protocol are done mainly through hard forks, without changing the economic rules of the Bitcoin . Bitcoin Cash will be a fork of the Bitcoin blockchain, one-to-one.
Bitcoin Cash (BCH) is an upgraded version of the Bitcoin Core software. It was released on August 1st, 2017. The main upgrade offered by Bitcoin Cash is an increase of the blocksize limit to 8mb. This effectively allows miners on the BCH chain to process more payments per second. This makes for faster, cheaper transactions and a much smoother user experience.