Ethereum is a decentralized system just like bitcoin. It is completely decentralized which means that there is no centralized authority controlling it. It is developed by Vitalik Buterin and uses a different approach when compared to bitcoin. Just like bitcoin, digital payments can be done on the platform. It uses smart contracts to automate legal contracts within two peers. dApps(decentralized apps) is an app that runs on Ethereum and use smart contracts to manage an organization or a specific part of the project.
What is Ethereum?