Ethereum co-founder Vitalik Buterin is reminding node operators to upgrade their clients before the Bellatrix “hard fork,” slated for Sept. 6. Buterin said that the scheduled upgrade will be the final update that prepares the Beacon Chain, the proof-of-stake (PoS) chain, for the Merge.
An Ethereum client is the software that allows Ethereum nodes to read blocks on the blockchain and smart contracts. A “node” is the running piece of the client software. In order to run a node, one has to first download an Ethereum client application. A node can be run by different Ethereum client software that varies in the programming language used and code base.