Just as the name sounds, Bitcoin cash is a hard fork from Bitcoin. It was developers from Bitcoin who did not agree to the segregated witnesses introduced by Bitcoin that moves for the hard fork.
Bitcoin cash provided a faster transaction by increasing the number of block sizes which also means increase in potential volume of transaction. This is also reduce energy consumption and as a result, lesser fee are charged on each transaction.
The truth is that people really adopted Bitcoin cash hoping it will even overtake the giant Bitcoin but since Bitcoin cash was also hard forked to form Another cryptocurrency project, it has not really regained it's strength.
It is worth saying though that Bitcoin cash is still among the first three cryptocurrencies to reckon with. Spending some money on Bitcoin cash can really help to increase value overtime.