Ethereum is a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of fraud or third party interference.
Ethereum is used to build decentralized applications (dapps) on its platform. A dapp is an application that runs on a decentralized network.
The most popular dapp built on Ethereum is Cryptokitties. Cryptokitties is a game where players can buy, sell, and breed digital cats.
The price of 1 Ethereum (ETH) is $1,228. Ethereum is the second largest cryptocurrency by market capitalization after Bitcoin.