Rising fees on the Bitcoin network contributed to a push by some in the community to create a hard fork to increase the blocksize. This push came to a head in July 2017 when some members of the bitcoin community including Roger Ver felt that adopting BIP 91 without increasing the block-size limit favored people who wanted to treat bitcoin as a digital investment rather than as a transactional currency. This push by some to increase the block size met a resistance. Since its inception up to July 2017, Bitcoin users had maintained a common set of rules for the cryptocurrency. Eventually, a group of bitcoin activists, investors, entrepreneurs, developers and largely China-based miners were unhappy with Bitcoin's proposed SegWit improvement plans meant to increase capacity and pushed forward alternative plans for a split which created Bitcoin Cash. The proposed split included a plan to increase the number of transactions its ledger can process by increasing the block size limit to eight megabytes.
Peer to peer (P2P) electronic cash is simply described as online money sent from one person to another without the need for a trusted third-party. As described in the original Bitcoin whitepaper by Satoshi Nakamoto, P2P cash makes use of digital signatures as part of the solution, but the main benefits are lost if a trusted third party is still required to prevent fraud. This makes P2P cash a trustless and safe way to transact without the need of intermediaries.
BCH is a cryptocurrency established as a result of the hard fork that took place to manage the scalability problem. Bitcoin Cash has a number of significant differences to Bitcoin: it is advertised as being faster and cheaper to use, the maximum block size is eight megabytes against one in previous Blockchain, and it has an emergency difficulty adjustment feature. Bitcoin Cash also uses 0-conf (or zero-conf) which allows for nearly instant transactions, meaning Bitcoin Cash transactions are almost always confirmed in the next block.
Both Bitcoin as well as Bitcoin Cash use a proof-of-work algorithm to timestamp every new block. The proof of work algorithm used is the same in both cases. It can be described as a partial inversion of a hash function. Additionally, both Bitcoin and Bitcoin Cash target a new block to be generated every ten minutes on average. The time needed to calculate a new block is influenced by a parameter called the mining difficulty. If the total amount of mining power increases, an increase of the mining difficulty can keep the block time roughly constant. Vice versa, if the mining power decreases, a decrease of the mining difficulty can keep the block time roughly constant.