The single most important issue currently facing the Ethereum network is scalability. The Ethereum network supports hundreds of decentralized applications. This means it needs to process a high number of transactions per second. In a recent speed test, the network only managed 20 transactions per second. By comparison, Visa’s maximum capacity is close to 24,000. A longer term issue is the sustainability of Proof of Work (PoW) and mining. Because each transaction on the Ethereum network uses about 30 kWh (Kilowatt hours). Furthermore, the electricity used by Ethereum mines could power over 650,000 American households every year. Ethereum 2.0 or Serenity, is a term used to describe a series of potential updates to Ethereum. For lack of better terms, to make it faster and better.