> From what I read, Bitcoin Cash is an alternative cryptocurrency like Ethereum, but based on a change to the original design of Bitcoin algorithms, which increased the basic block size of the transactions. It seems this was done to increase transaction performance.
It is an altcoin, but unlike most altcoins it has a shared history with Bitcoin. Basically, at the moment of it's creation (today, August 1st), everone who owned bitcoins owned an equal number of Bitcoin Cash. So now they are two separate coins and two separate chains, but with a shared history.
> Is this a good thing or a bad thing?
It's hard to give a judgement. When Apple started working on a self-driving car, was that a good thing or a bad thing? Hard to say, it more of just was a thing to know, unless you had a horse in the self-driving car race. Bitcoin Cash will either be successful in some capacity or it will flop altogether, but the original Bitcoin certainly isn't going anywhere.
If you don't have a horse in the race, I wouldn't think of it as a good or bad thing. It's just an event that doesn't mean too much unless you are excited about Bitcoin Cash and the principles it stands for, or if you have Bitcoin and don't realize that you also have an equivalent number of Bitcoin Cash (currently trading at like $200 each - a nontrivial sum!)
Labels such as "altcoin" are propaganda. It does nothing to describe actual physical/technical properties of a chain. It is only meant as a tool to alter people's perceptions of a coin.
Is this kind of like having a new denomination of currency? For example, why carry around 10 $1 bills when I can carry around one $10 bill?
If the number of bitcoins you have stays the same, but just the block size of storage in transaction changes, then I'd guess it's very similar to a bigger unit of currency.
No, not quite. It's like having $25 in your wallet in USD, and then next time you look at your wallet you have $25 in USD and also $25 in USD-different. Then you go to the store and find out they only accept USD, and not USD-different, but if you go to a currency exchange you can trade your USD-different for $1 or $2 in USD each.
Not a great analogy I guess, but the point is that it's definitely not the same as having a new denomination of currency. It's a whole new currency entirely, it's just that everyone who had Bitcoin was "granted" (sorta) this new currency too, in the same volume that they had the old currency.
I find it interesting that the two split and then essentially float as different currencies at different rates. Surely, there will be some inter-relationship between them as well.
It has the momentum and the majority mining (hash) power behind it, which is the most important thing in a cryptocurrency using proof of work. That said, nothing in this life is actually certain, and major flaws in Segwit could be found that cause the power to flip over to BCC and BTC could end up going down the drain. Or both BTC and BCC could lose out to Etherium or the USD or gold. Nobody knows the future, but the easy money is on BTC remaining the lead horse in this race.
It is an altcoin, but unlike most altcoins it has a shared history with Bitcoin. Basically, at the moment of it's creation (today, August 1st), everone who owned bitcoins owned an equal number of Bitcoin Cash. So now they are two separate coins and two separate chains, but with a shared history.
> Is this a good thing or a bad thing?
It's hard to give a judgement. When Apple started working on a self-driving car, was that a good thing or a bad thing? Hard to say, it more of just was a thing to know, unless you had a horse in the self-driving car race. Bitcoin Cash will either be successful in some capacity or it will flop altogether, but the original Bitcoin certainly isn't going anywhere.
If you don't have a horse in the race, I wouldn't think of it as a good or bad thing. It's just an event that doesn't mean too much unless you are excited about Bitcoin Cash and the principles it stands for, or if you have Bitcoin and don't realize that you also have an equivalent number of Bitcoin Cash (currently trading at like $200 each - a nontrivial sum!)