Ethereum

Ethereum is a blockchain launched in July 2015 by Vitalik Buterin and a group of co-founders. Where Bitcoin was designed mainly to move value, Ethereum was designed to run programs. Developers deploy small pieces of code called smart contracts, and anyone can interact with them. This is the foundation for most decentralized finance (DeFi) applications, NFTs, stablecoins, and thousands of tokens.

The native coin is ether, with the ticker ETH. Every action on the network costs a fee called gas that is paid in ETH. In September 2022 Ethereum switched from proof of work to proof of stake in an upgrade known as the Merge, cutting its energy use by well over 99 percent. Since then the network has been secured by validators who lock up ETH instead of miners who burn electricity.

Ethereum has no fixed maximum supply, but part of every transaction fee is permanently destroyed, which offsets the new ETH paid to validators. Because the base network can be slow and expensive during busy periods, much activity has moved to layer 2 networks such as Arbitrum, Optimism, and Base that settle back to Ethereum.