Ethereum is a public blockchain-based distributed computing platform, featuring smart contract functionality. It provides a decentralized virtual machine, the Ethereum Virtual Machine (EVM), which can execute scripts using an international network of public nodes.

Ethereum also provides a cryptocurrency token called “Ether”, which can be transferred between accounts and used to compensate participant nodes for computations performed. “Gas”, an internal transaction pricing mechanism, is used to mitigate spam and allocate resources on the network.

Ethereum was proposed in 2013 by Vitalik Buterin, a cryptocurrency researcher and programmer. Development was funded by an online crowdsale that took place between July and August 2014. The system went live on 30 July 2015, with 72 million coins “premined”. This accounts for about 70 percent of the total circulating supply in 2019.

In 2016, as a result of the collapse of The DAO project, Ethereum was split into two separate blockchains – the new separate version became Ethereum (ETH), and the original continued as Ethereum Classic (ETC). The value of the ETH token grew to over US$1400 during 2017 before dropping below US$100 in early 2018.

The dag size is currently 2.1 GB as of December 2018 and is expected to grow to be around 10 GB in 2020.

This increase is due to the increase in mining difficulty as more miners join the network and try to mine blocks. The larger the dag size, the more difficult it becomes to mine blocks, and as a result, miners need more powerful hardware to be able to mine blocks in a timely manner.