Overview
Bitcoin Cash was created as a result of a continuing debate in the Bitcoin community about how Bitcoin should scale to meet an expanding user base. Bitcoin Cash branched off from the original Bitcoin blockchain, and all work done previous to the split is just as much part of the history of Bitcoin Cash as it is part of the history of Bitcoin. Because of this shared history, and the disagreements that led to its creation, the status of Bitcoin Cash is hotly debated, with two sides deeply entrenched in their view.
Proponents of Bitcoin Cash believe that they preserved the original Bitcoin by forking off before other controversial changes were applied, mainly the SegWit side chain system. In their view, Bitcoin Cash conforms more to the original version of Bitcoin, and some even go so far as to say it is the true Bitcoin.
Opponents of Bitcoin Cash feel that it was a fork perpetrated by people looking to capitalize on Bitcoin's success by creating what is essentially just another coin in the market, but unfairly leveraging the name recognition of Bitcoin.
Purpose
Bitcoin Cash has a very clear and simple goal, which is to be an every day currency, used as commonly and frequently as any paper cash, credit card, or any other way people transact for goods and services. However, this goal does not exclude the possibility of being a store of value, as proponents of Bitcoin Cash believe that value ensues from the ability to conduct commerce. Also, as of mid-May 2018, Bitcoin Cash will have the ability to do smart contracts similar to what Ethereum can do, and previous to this, developers have already innovated different uses for the Bitcoin Cash blockchain, such as an on chain social messaging system. What turns out to be the most popular use for Bitcoin Cash may yet to be seen.
Technical
Bitcoin Cash is mined on the exact same hardware that Bitcoin uses, as they are both forks of the exact same codebase. As such, Bitcoin Cash directly competes with Bitcoin for computing power. How much power is split between the two coins is determined by the price of the coins, which determines how profitable they are to mine. Currently the majority of mining power goes to Bitcoin, as it has a significant price advantage. However, Bitcoin Cash has seen price gains approaching 20% the value of Bitcoin. If it goes upward, and there is enough incentive for Mining to switch over to Bitcoin Cash, this could present a technical challenge for Bitcoin, as the difficulty algorithm that determines how fast blocks can be mined might not adjust in time to match less computing power being available. In such a case, the Bitcoin chain could see a dramatic fall in value, or even fail to be able to continue entirely. This is one reason Bitcoin supporters feel that Bitcoin Cash is an existential threat to Bitcoin.
Market
Except for a few very short lived spikes, Bitcoin Cash has held a fairly consistent place as the fourth largest cryptocurrency by market capitalization. As of May 2018, it has closed the gap on Ripple, its price deviating slightly from the rest of the market, which usually tends to rise and fall together. Because of the controversy surrounding Bitcoin, there are those who apply a lot of meaning to its rise or fall, but while the two warring factions rally against the opposing side, hoping to see Bitcoin Cash rapidly become the de facto cryptocurrency or disappear completely, the market seems to have settled on a slow and steady progression that leaves neither side completely satisfied.