BCH or Bitcoin Cash was created by updating the Bitcoin protocol code as a result of the hard fork on August 1, 2017. According to the official version of the initiators of this update, they created their solution (Bitcoin Cash) in case "something goes wrong" as a result of the bitcoin network update - SegWit2x.
Technologically, BCH is able to process more transactions in less time interval than BTC, this in turn influenced the cost of transactions in Bitcoin Cash network, which are lower than in bitcoin network.
BCH is traded on many cryptocurrency exchanges and is easy to buy and sell.