What is Ether ?
The English word for Ethereum is Ether and the currency abbreviation is ETH，Ether is the underlying currency of the blockchain platform Ether is an important element used to drive the entire operation of Ether, including mining, calculating transaction fees and other work need to be supported by Ether, so when talking about what Ether is, it is the same as understanding what is Ethereum first.

What is Ethereum?
Vitalik Buterin, the founder of Ethereum, says that Ethereum is a decentralized mining network and software development platform rolled into one, which means that not only does it have a public chain system that can be mined like Bitcoin, but you can also develop your own applications on it. So Ether is also a blockchain public chain platform when it is released, just like Bitcoin, but the most important feature of Ether is that it has "smart contracts" and the ability to write "Dapp" (Decentralized Application) outside the blockchain, which are the two most important concepts of Ether.

Explanation of Ethernet's Dapp and Smart Contracts
Dapp is a decentralized application, for example, all the apps on mobile phones or mini-games on computers today, there is a server on the backend of the software company that publishes them to support the operation of the whole program.

So why was the Dapp created?
If there is a mini-game that you care about today, for example a dice game where the assets are bought with real money and the profits earned are actually converted into real money, would you care a lot about the fairness of the game? If everything is running on the server of the company that publishes the software, how do I know that they are not secretly adjusting the odds of the dice hitting the numbers in the game? So if the dice game is written as a Dapp today, then the program can be made public to everyone, so that everyone can prove that the rules of the game in the program are very fair, and then the game can be put on the blockchain, so that no one can secretly change any items in the program, not even the publisher itself. This way, everyone can participate in this completely decentralized game with confidence. Once you understand what Dapp is, smart contracts are related to Dapp habits. Smart contracts can be said to be a bridge between Dapp and the blockchain network, a technology that puts program logic on the blockchain. For example, if someone makes money on the game, the message that the Dapp will send to the Ethereum may be which person and how much money he has made, and then the smart contract on the Ethereum will automatically perform the change of the balance in the electronic account, that is, increase the money in his account. A smart contract is a program that runs on the blockchain network. On Ether, smart contracts use a new language, Solidity, which is unique to Ether.

What is the role of Ethereum ?
As mentioned in the previous chapter, a smart contract is a program that runs on the blockchain network, and running a program on the blockchain network consumes everyone's computing resources, so if you want to run a smart contract on the blockchain, you have to pay for these computing resources. In addition to that, to send a transaction on the Ethereum blockchain, the same transaction fees are charged as on the bitcoin blockchain, and this transaction fee is also paid in Ethereum instead, and the reward for mining on Ethereum will also be Ethereum (currently the reward for mining a block is 2 Ethereum), so in short, Ethereum is the same currency as bitcoin, and it is also the same currency that drives a public blockchain network, but Ethereum has the additional feature of being responsible for smart contract payments.