Bitcoin Cash is one of the most successful hard forks1 of Bitcoin. Similar to Bitcoin, Bitcoin Cash is a peer-to-peer (P2P) digital currency and payment network that is decentralized and supported by an open-source blockchain protocol. In order to enable the two networks to coexist concurrently and independently of one another, software modifications were integrated into the creation of Bitcoin Cash on August 1, 2017, under the direction of a group of developers worried about Bitcoin’s capacity to scale transaction throughput effectively. The codebase is currently being maintained and improved by numerous developer teams. 2
Bitcoin Cash has climbed above the cluttered digital currency scene to become the fourth largest network by market cap as a consequence of generous mining incentives and backing from notable, vocal critics of Bitcoin’s method of achieving scalability.3

1 Forks are modifications to the source code of a network protocol and there are two main types. Soft forks are software upgrades to the main protocol and are backwards-compatible. The implementation of Segregated Witness (SegWit) to the Bitcoin network in August 2017 is a prime example of this. Hard forks result in the creation of an entirely new blockchain, allowing for two currencies to exist concurrently, and are not backwards-compatible. Two examples of hard forks of the Bitcoin network are Bitcoin Cash and Bitcoin Gold, formed in August 2017 and October 2017, respectively.
2 Bitcoin ABC.
3 As of September 30, 2019.