Ethereum is an open software platform that enables developers to build and deploy decentralized applications.
The Ethereum blockchain is focused on running the programming code of any decentralized application.
When mining the Ethereum blockchain, you earn Ether. Ether is a type of crypto token that fuels the network. It is also used by application developers to pay for transaction fees and services of the Ethereum network.
Any centralized service can be decentralized by using Ethereum. ethereum.org