Ethereum is a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of fraud or third party interference.
These apps run on a custom built blockchain, an enormously powerful shared global infrastructure that can move value around and represent the ownership of property. This enables developers to create markets, store registries of debts or promises, move funds in accordance with instructions given long in the past (like a will or a futures contract) and many other things that have not been invented yet, all without a middleman or counterparty risk.
The project was bootstrapped via an ether presale in August 2014 by fans all around the world. It is developed by the Ethereum Foundation, a Swiss non-profit, with contributions from great minds across the globe.
Ethereum is not just a platform but also a programming language (Turing complete) running on a blockchain that helps developers to build and publish distributed applications. The advantage of Ethereum over Bitcoin, or other public blockchains, is that it allows for much more complex smart contracts.
In order to make sure that these contracts execute as intended, Ethereum miners validate and execute these instructions on the network and get rewarded with ether for their efforts. Who owns Ethereum network? No one owns the Ethereum network much like no one owns the technology behind email.
The Ethereum network is kept running by computers all over the world called “nodes”. Anyone can run an Ethereum node and help process transactions on the network to keep things running smoothly.
The project is led by Vitalik Buterin, who was born in Russia but grew up in Canada. He now lives in Singapore where he works on Ethereum full time with help from hundreds of other talented people from around the world.
While there is no one central authority that controls Ethereum network, there is still a core team of developers who are responsible for its upkeep and continued development. The team is spread out across the globe with members in Europe, North America, Asia, and Australia.
The Ethereum Foundation is a non-profit organization registered in Switzerland whose main goal is to support Ethereum platform and ecosystem development. They are also responsible for managing funding raised from ether presale and various grants and donations received from supporters of the project.
So while there is no one person or organization who owns Ethereum network, there is a community of passionate individuals from all over the world working together to keep it running and continue to build new applications on top of it.