A major split of the Ethereum blockchain network. In 2016, a year after its introduction, Ethereum was hard forked. The original Ethereum protocol became Ethereum Classic and adopted the ETC symbol. The new network retained the original ETH symbol and became the version most people use. ETH has a market cap at least 50 times that of ETC. See
Ethereum Classic.
In August 2021, the London hard fork added five improvements to Ethereum (ETH) and required all Ethereum nodes to upgrade. Ethereum 2.0 is also a huge change to Ethereum. See
London hard fork,
Ethereum 2.0 and
Ethereum.