Bitcoin Cash came about during the great "block-size" debate of 2017. Bitcoin had some serious scalability issues and a segment of the community believed that the solution was to increase the individual block size of the Bitcoin blockchain. This segment forked off from the main Bitcoin blockchain on August 1, 2017, to create Bitcoin Cash with an 8 Mb block size as opposed to BTC's 1 Mb.
Quite like Bitcoin, Bitcoin Cash uses a proof-of-work (PoW) consensus mechanism, has a 10 min block time, and a max supply of 21 million. During the 2017 hard fork, every wallet holding BTC received an equal amount of BCH. Recently, the Bitcoin Cash protocol was split into Bitcoin SV (Bitcoin Satoshi Vision) and Bitcoin Cash with a 32 Mb block size.