CoinMarketCap: What is Ethereum or ETH?
How does CoinmareketCap Work. Ethereum is a technology that lets you send cryptocurrency to anyone for a small fee. It also powers applications that everyone can use and no one can take down.
It's the world's programmable blockchain.
Ethereum builds on Bitcoin's innovation, with some big differences.
Both let you use digital money without payment providers or banks. But Ethereum is programmable, so you can also use it for lots of different digital assets – even Bitcoin!
This also means Ethereum is for more than payments. It's a marketplace of financial services, games and apps that can't steal your data or censor you.
Forks are when major technical upgrades or changes need to be made to the network – they typically stem from Ethereum Improvement Proposals (EIPs) and change the "rules" of the protocol.
When upgrades are needed in traditional, centrally-controlled software, the company will just publish a new version for the end-user. Blockchains work differently because there is no central ownership. Ethereum clients must update their software to implement the new fork rules. Plus block creators (miners in a proof-of-work world, validators in a proof-of-stake world) and nodes must create blocks and validate against the new rules. More on consensus mechanisms
These rule changes may create a temporary split in the network. New blocks could be produced according to the new rules or the old ones. Forks are usually agreed upon ahead of time so that clients adopt the changes in unison and the fork with the upgrades becomes the main chain. However, in rare cases, disagreements over forks can cause the network to permanently split – most notably the creation of Ethereum Classic with the DAO fork.