Bitcoin Cash was created in 2017 by a hard fork from the original Bitcoin blockchain. Its symbol is BCH.
The main difference between "Bitcoin" and "Bitcoin Cash" is the increased block size of "Bitcoin Cash".
It tried to become the new Bitcoin, but the response from the Bitcoin community was negative by the majority of the market. Which resulted in a massive sell off.
Bitcoin Cash remains as a novelty altcoin that is still traded on many Bitcoin exchanges. Mainly propped up by a few pump and dumps now and then.
The proponents of this altcoin used the name "Bitcoin" in its name "Bitcoin Cash" to try to legitimize it as the new real Bitcoin which is a scheme that has been adopted to other altcoins. But many people call it "Bcash", "Btrash" or simply "a scam".