Ethereum is a decentralized blockchain platform that was created in 2015 by Vitalik Buterin. Like Bitcoin, Ethereum is a decentralized cryptocurrency that uses blockchain technology to maintain secure transactions.
Like Bitcoin, Ethereum is also used as a deposit/withdrawal method to online casinos.
Ethereum is a bit different compared to bitcoin. Basically, bitcoin was created to support fast and secured transactions, while ethereum is more a platform for decentralized applications (dApps) and smart contracts.
Using cryptocurrencies as a deposit method to play in an online casino has some advantages such as fast transactions, higher bonuses, in some cases provably fair games etc.