Bitcoin Cash was created August 1st 2017, Bitcoin Cash is a result from a fork in the Bitcoin network. The reason Bitcoin cash was created is because Bitcoin or Bitcoin core as it is being referred to by, Has changed to much over the years, Thr original purpose of Bitcoin as laid out by Satoshi Nakamoto is to be a peer-to-peer cash system. Currently Bitcoin core is not that, Bitcoin core has high fees, slow transaction times and is the first blockchain in the history of blockchains to have full blocks
Bitcoin cash was forked by a community who wanted to keep Bitcoin to its intended state. Bitcoin cash allows for fast and cheap transactions and has a block size of 8 MB which will scale with the demand, just as Bitcoin did in the past.
If you head to bitcoin.com you will find a huge amount of information on all things cryptocurrency. But what you will also find is a tone of stuff enplaning why Bitcoin cash is Bitcoin. Roger ver the CEO of bitcoin.com was the first investor in the world to invest in Bitcoin. He was a major player in the space for many years, and still is. However he is now 100% backing Bitcoin cash over Bitcoin.
Because Bitcoin cash is a fork of Bitcoin, it still shares the same blockchain, This means that there will still only ever be 21million Bitcoin cash. However it is becoming more and more popular for miners to mine Bitcoin cash over Bitcoin, and we are seeing that result in the drop in market cap on Bitcoin. Bitcoin used to control 90% of the entire market cap, At the time of writing it is down to about 30%. Roger via recently said "I would be surprised if Bitcoin cash doesnt surpass Bitcoin this year." I would recommend you check out some videos by roger ver. You can see them here
As Bitcoin cash is a fork from Bitcoin, They are trying to stay as close as possible to Satoshis white paper, Which you can read up on here