Bitcoin Cash (BCH) is hard fork (a community-activated update to the protocol or code) of Bitcoin that took effect on August 1st, 2017 that increased the block size to 8MB, to help the scale the underlying technology of Bitcoin.Nov 16th 2018: BCH was hard forked again and split into Bitcoin SV and Bitcoin ABC. Bitcoin ABC became the dominant chain and took over the BCH ticker as it had more hashpower and majority of the nodes in the network.
There are two factions of bitcoin supporters, that support large blocks or small blocks.[20] The Bitcoin Cash faction favors the use of its currency as a medium of exchange for commerce while the Bitcoin-supporting faction view bitcoin's primary use as that of a store of value.[20] Some Bitcoin supporters like to call Bitcoin Cash “Bcash,” “Btrash,” or simply a scam, while Bitcoin Cash advocates insist that their implementation is the pure form of Bitcoin.[20]


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.


从广义上来看,网络交换机分为两种:广域网交换机和局域网交换机。广域网交换机主要应用于电信领域,提供通信用的基础平台。而局域网交换机则应用于局域网络,用于连接终端设备,如PC机及网络打印机等。从传输介质和传输速度上可分为以太网交换机、快速以太网交换机、千兆以太网交换机、FDDI交换机、ATM交换机和令牌环交换机等。从规模应用上又可分为企业级交换机、部门级交换机和工作组交换机等。各厂商划分的尺度并不是完全一致的,一般来讲,企业级交换机都是机架式,部门级交换机可以是机架式(插槽数较少),也可以是固定配置式,而工作组级交换机为固定配置式(功能较为简单)。另一方面,从应用的规模来看,作为骨干交换机时,支持500个信息点以上大型企业应用的交换机为企业级交换机,支持300个信息点以下中型企业的交换机为部门级交换机,而支持100个信息点以内的交换机为工作组级交换机。 [3] 


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 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, 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. Bitcoin cash is not one of the fastest cryptocurrency per transaction. And it is good investment for economic crisis.