Ethereum is a decentralized, open-source blockchain platform that enables the creation of smart contracts and decentralized applications (dapps). It was created in 2015 by Vitalik Buterin, a programmer and cryptocurrency researcher.

Ethereum is often referred to as the “World Computer” because it allows developers to build and deploy applications on its blockchain network. This means that these applications run on a decentralized network, rather than on a single central server, making them more secure and resistant to censorship.

One of the key features of Ethereum is the use of its native cryptocurrency, Ether (ETH), which is used to pay for transactions and computational services on the network. This incentivizes users to contribute computing power to the network, helping to keep it secure and decentralized.

Ethereum also allows for the creation of custom tokens, which can be used for a variety of purposes such as representing assets like property or stocks, or for use as a currency within decentralized applications.

In summary, Ethereum is a blockchain platform that enables the creation of decentralized applications and the use of custom tokens. It is designed to be a more secure and censorship-resistant alternative to traditional centralized systems, and is powered by its native cryptocurrency, Ether.