Ethereum is a decentralised network that nobody owns. However, Ethereum’s currency, Ether (ETH) is owned by people and needed by people who want to send a transaction on the Ethereum blockchain. This transaction uses Ethereum Gas.
Like Bitcoin, ETH is a currency that can be transacted without the need for third party involvement. Unlike Bitcoin, however, instead of operating only as a currency, it is needed by programmers building on Ethereum. This is as fuel for their Ethereum decentralised application (dApp).
How Many Are There?
Unlike Bitcoin, which has a set limit of 21 million BTC, Ethereum has an inflationary system with no set cap.
At time of writing, there are 110,564,856 ETH in circulation. 60 million were purchased during the crowdfunding campaign back in 2014. And 12 million went to the Ethereum Foundation, which is a group of developers working on the blockchain.
Every 12 seconds, 2 ETH are minted and are allotted to miners for the block reward. However, it’s believed that the block reward will fall to 1 ETH in 2021. Read at Ethereum Nexus