Ethereum is a decentralized, open-source blockchain platform that enables the development of smart contracts and decentralized applications (DApps). It was proposed by Vitalik Buterin in late 2013 and launched in 2015.

Unlike Bitcoin, which primarily serves as a digital currency, Ethereum's primary focus is to provide a platform for executing programmable smart contracts. Smart contracts are self-executing agreements with predefined rules and conditions. They automatically execute when the conditions encoded within them are met. This allows for the creation of various decentralized applications and tokens on the Ethereum blockchain.

Ethereum introduced its native cryptocurrency called Ether (ETH), which is used to fuel operations and execute smart contracts on the network. ETH is also tradable on cryptocurrency exchanges and can be used as a digital asset.

One of Ethereum's key features is its ability to create and deploy decentralized applications. Developers can use Ethereum's programming language, Solidity, to build and deploy smart contracts and DApps. These applications can cover a wide range of use cases, including decentralized finance (DeFi), non-fungible tokens (NFTs), gaming, identity verification, supply chain management, and more.

Ethereum has undergone several upgrades to improve scalability, security, and functionality. The most significant upgrade to date is Ethereum 2.0, also known as ETH2 or Serenity. This upgrade aims to transition the network from a proof-of-work (PoW) consensus mechanism to a proof-of-stake (PoS) mechanism, which will make the network more energy-efficient and scalable.

Ethereum's impact on the blockchain industry has been significant, as it has paved the way for the development of decentralized applications and the broader adoption of blockchain technology. It has also spurred the growth of the DeFi ecosystem, enabling various financial services such as lending, borrowing, and decentralized exchanges.

It's important to note that while I strive to provide up-to-date information, the cryptocurrency and blockchain space can evolve rapidly. Therefore, it's always recommended to consult official sources and stay informed about the latest developments in Ethereum and other cryptocurrencies.