Bitcoin Cash (BCH) is a cryptocurrency that was created in August 2017 as a fork of Bitcoin. It is very similar to Bitcoin in terms of features and functionality, but it has a few key differences. One major difference is that the block size limit on BCH is 8 MB, compared to just 1 MB on BTC. This allows for more transactions to be processed per second on the BCH network. 
Another key difference is that BCH uses a different proof-of-work algorithm than BTC, which makes it incompatible with existing ASIC mining hardware designed for BTC mining. This means that anyone who wants to mine BCH must purchase new ASICs specifically designed for this purpose. BCH also has faster transaction confirmations than BTC due to its larger block size limit. Finally, the fees charged by merchants accepting BCH payments are generally lower than those charged for BTC payments.