Bitcoin Cash (BCH) is a peer-to-peer electronic cash system, which aims to enable “new economies with low fee micro-transactions, large business transactions, and permissionless spending”.
Bitcoin Cash originated from an upgrade proposal of Bitcoin, that increased the maximum block size from 1 megabyte to 8 megabytes, which ultimately led to a hard-fork on August 1st, 2017 . Since then, additional changes have been approved, such as a new difficulty adjustment algorithm, the support of new opcodes, Schnorr Signatures, and further extensions in the block size.
Bitcoin Cash uses the same SHA-256d-based Proof-of-Work consensus mechanism as Bitcoin. Bitcoin Cash also has a target block time of 10 minutes, and its total supply is capped at 21 million.
On November 16th 2018, the Bitcoin Cash blockchain withstood another hard-fork, which resulted in a chain split into Bitcoin Cash SV and Bitcoin Cash ABC. Since then, Bitcoin Cash ABC has commonly used the BCH ticker and referred to as Bitcoin Cash.
The Bitcoin Cash network has protocol upgrades twice a year, on November 15th and May 15th. These upgrades are required for all node operators . For instance, on May 15th 2018, Bitcoin Cash upgraded to increase its block size to 32 megabytes.