An etf is the abbreviation for an exchange-traded open-ended index fund, often referred to as an exchange-traded fund, which is an open-ended fund with variable shares traded on an exchange.
Ethereum is more effective than pure cryptocurrency. Through Ethereum, users can create any decentralized application (i.e. DApp) and smart contract. Theoretically, programmable Ethereum can be used for any economic or governance activities.
In short, Ethereum is similar to the blockchain version of Android and iOS systems, a blockchain APP platform. Ethereum is a global open source platform for decentralized applications (DApp). The name comes from Ether and the suffix ruem (Greek meaning is "oil")