Ethereum (ETH) was released in 2015 and is after Bitcoin the second largest cryptocurrency in the world. However, unlike Bitcoin, Ethereum is not just a digital currency. The Ethereum blockchain is a decentralized system that offers programming, management and execution of decentralized programs such as smart contracts. Ethereum is based on the proof of stake concept, which makes staking possible. Due to the so-called DAO-Hack in 2016, a hard fork took place on the Ethereum blockchain, resulting in Ethereum Classic.