Bitcoin Cash is a cryptocurrency that split off from Bitcoin in 2017 over a long-running argument about how the network should grow. Like Bitcoin, it runs on a decentralized network that records transactions on a public blockchain using proof of work, and it shares Bitcoin's 21 million coin supply cap. What sets it apart is a deliberate choice to make blocks larger so the network can handle more payments at once.
The split happened on August 1, 2017, at block 478,559. Up to that point both coins shared the same history and the same ledger. From that block on, they went their separate ways. Anyone who held Bitcoin at the time of the fork also received an equal amount of Bitcoin Cash, since the two chains shared everything before the break.
The reason for the fork was a disagreement that had been building for years. Bitcoin blocks were limited to one megabyte, which capped how many transactions could be processed in a given window and pushed fees up when the network got busy. One camp wanted to keep blocks small and handle scaling with other tools, treating Bitcoin mainly as a store of value. Another camp, made up of activists, developers, and miners, wanted bigger blocks so the coin could work as everyday electronic cash. When the two sides could not agree, the second group created Bitcoin Cash.
Bitcoin Cash raised the block size limit to eight megabytes at launch, eight times Bitcoin's limit at the time. In 2018 that ceiling was raised again, from 8MB to 32MB. Larger blocks were meant to fit more transactions into each block and keep fees low even when usage rises.
The intended use follows directly from that design. Supporters built Bitcoin Cash to be spent, a medium of exchange for buying things and sending money rather than mainly a long-term holding. The technical setup, proof of work using the SHA-256 hashing function and the same 21 million cap, is close to Bitcoin's, so the experience of using it feels familiar to anyone who knows the original.
Because it came directly out of Bitcoin's source code and history, Bitcoin Cash is one of the clearest examples of a hard fork in crypto: a permanent split where a single chain becomes two, each carrying its own rules forward. It remains tied to the broader debate it grew out of, the question of whether a coin like Bitcoin is better used as digital gold to hold or as digital cash to spend.