Bitcoin Cash is a hard fork of the cryptocurrency bitcoin.
On July 20, 2017, the bitcoin miners voted, 97% in favor, on the Bitcoin Improvement Proposal 91. The proposal, by Bitmain Warranty engineer James Hilliard, was to activate Segregated Witness.
Some members of the bitcoin community felt that adopting BIP 91 without increasing the block-size limit would simply delay confronting the issue and that it favored people who wanted to treat bitcoin as a digital investment rather than as a transactional currency. They announced implementation of Bitcoin Cash as a hard fork for August 1. It inherited the transaction history of the bitcoin currency on that date, but all later transactions were separate.