Bitcoin Cash was created as an answer to the years-long debate among the Bitcoin community regarding the best way to scale Bitcoin to more users. The simplest solution, and the one adopted by Bitcoin Cash, is to increase the Max Block size Limit parameter of the Bitcoin codebase. While Bitcoin’s block size limit remains at 1 megabyte (allowing for ~250,000 transactions per day), Bitcoin Cash has increased the limit to 8MB, allowing for around two million transactions to be processed per day.
As far as the users of Bitcoin/Bitcoin Cash are concerned there is very little noticeable difference on the frontend when using either currency. The main difference between these coins is the fact that, given equal hash rate, BCH protocol allows for more transactions per second which translates to faster payments and lower fees.
Bitcoin Cash brings sound money to the world, fulfilling the original promise of Bitcoin as "Peer-to-Peer Electronic Cash". Merchants and users are empowered with low fees and reliable confirmations. The future shines brightly with unrestricted growth, global adoption, permissionless innovation, and decentralized development.
All Bitcoin holders as of block 478558 are also owners of Bitcoin Cash. All are welcome to join the Bitcoin Cash community as we move forward in creating sound money accessible to the whole world.
On Chain Scalability - Bitcoin Cash follows the Nakamoto roadmap of global adoption with on-chain scaling. As a first step, the blocksize limit has been made adjustable, with an increased default of 8MB. Research is underway to allow massive future increases.
New Transaction Signatures - A new SigHash type provides replay protection, improved hardware wallet security, and elimination of the quadratic hashing problem.
New Difficulty Adjustment Algorithm (DAA) - Responsive Proof-of-Work difficulty adjustment allows miners to migrate from the legacy Bitcoin chain as desired, while providing protection against hashrate fluctuations.
Decentralized Development - With multiple independent teams of developers providing software implementations, the future is secure. Bitcoin Cash is resistant to political and social attacks on protocol development. No single group or project can control it. The bitcoin-ml mailing list is a good venue for making proposals for changes that require coordination across development teams.
Is Bitcoin Cash different from 'Bitcoin'?
Yes. Bitcoin Cash is the continuation of the Bitcoin project as peer-to-peer digital cash. It is a fork of the Bitcoin blockchain ledger, with upgraded consensus rules that allow it to grow and scale.
If I own Bitcoin, do I automatically own Bitcoin Cash too?
Anyone who held Bitcoin at the time Bitcoin Cash was created became owners of Bitcoin Cash. This means that Bitcoin holders as of block 478558 (August 1st, 2017 about 13:16 UTC) have the same amount of Bitcoin Cash as they had Bitcoin at that time. If your Bitcoins are stored by a third party such as an exchange, then you must inquire with them about your Bitcoin Cash.
Any transactions after the August 1st ledger split are completely separate between Bitcoin and Bitcoin Cash. This means any Bitcoin acquired after the split does not include any Bitcoin Cash, and any Bitcoin Cash does not include any Bitcoin.