Ethereum is a distributed network with a built-in flexible programming language allowing contracts, programs, and applications to be encoded into its blockchain. The platform thus functions as something of a distributed "world computer", continually running the systems created by its users. The native asset - Ether - is used to pay for computation time on the network.
Get into the finer details of Ethereum with this comprehensive paper which explains why & how Ethereum was created.
Find answers to recurring questions and myths about Ethereum.
Ethereum's mining concept is a tad different from other cryptocurrencies. Learn more about Ethash and other mining-related concepts.