Ethereum is a decentralized blockchain platform that launched in 2015, created by Vitalik Buterin and a team of developers. Unlike Bitcoin, which was designed primarily as digital money, Ethereum was built as a programmable blockchain. That means it lets developers run code called *smart contracts* — self-executing agreements that run exactly as written without middlemen.

The native currency is *ETH*, used to pay for transactions and computation on the network. Every action, from sending tokens to minting an NFT, requires “gas”, a fee paid in ETH that compensates validators for processing and securing the network.

In 2022 Ethereum completed “The Merge”, shifting from energy-heavy proof-of-work to *proof-of-stake*. Now validators lock up ETH to secure the network and earn rewards, cutting energy use by over 99%. This made Ethereum more scalable and environmentally sustainable.

Ethereum is the foundation for most of *DeFi* — decentralized finance — including lending, borrowing, and trading without banks. It also powers NFTs, DAOs, gaming, and tokenized assets. Its open-source nature means anyone can build applications on it, creating a global, permissionless ecosystem.

The network continues evolving with upgrades like sharding and Layer-2 scaling solutions such as Arbitrum and Optimism to handle more transactions at lower cost. At its core, Ethereum aims to be a world computer: a trustless platform where code, not institutions, enforces rules.