Ethereum ETH: Hard Fork

Don't forget to update your nodes to version 1.11.7 or above before the Arrow Glacier mainnet hard fork! 
Block number: 13,773,000 
ETA: 09.December 2021, 20:30

The cryptocurrency mainnet operates according to certain rules. To improve network performance or correct errors, it is periodically made changes. A hard fork is changes that are not compatible with previous versions of programs that support the cryptocurrency network and in order to continue to mine cryptocurrency, miners need to update the software.

In some situations, as a result of a hard fork, a completely new cryptocurrency may appear, as happened with Bitcoin Cash.