Ethereum is an open-source public service that makes use of blockchain technology to facilitate smart contracts and cryptocurrency trading securely without a third party. There seem to be 2 accounts available through Ethereum: externally owned accounts (controlled by private keys influenced by human users) and contract accounts.
Ethereum was created with the purpose to enable developers to build and publish smart contracts and distributed applications (dApps) that can be used without the risks of downtime, fraud, or interference from a third party.
Ethereum is also described as “the world’s programmable blockchain.” It distinguishes itself from Bitcoin as a programmable network that serves as a marketplace for financial services, games, and apps, all of which can be paid for in Ether cryptocurrency and are safe from fraud, theft, or censorship.
Ethereum is the second-largest cryptocurrency by volume, but its many uses can create a much larger learning curve for new investors than Bitcoin.