Table of contents
What is blockchain?
A blockchain is a database of transactions that is updated and shared among many computers in a network. Each time a new set of transactions is added, it's called a "block," from which the blockchain gets its name. Most blockchains are public, and users can only add data, not delete it. If someone wants to change any information on the system or trick the system, he needs to be able to do so on most of the computers in the network. That would be a huge project. This makes established blockchains such as Ethereum very secure.
What is Ethereum?
Ethereum is a technology for building applications and organizations, holding assets, transacting, and communicating without the control of a centralized regulatory authority. No personal details are required to use Ethereum, and users control their own data and what they share. Ethereum has its own cryptocurrency, Ether, which is used to pay for certain activities on the Ethereum network.
What are cryptocurrencies?
Cryptocurrency, short for cyptocurrency, is a new form of digital currency based on encryption technology.
Cryptocurrency originated from Bitcoin in 2008. You can use cryptocurrency to send money to anyone anywhere in the world. Unlike regular bank transfers or other financial services like Paypal and Alipay, cryptocurrencies do not require a middleman, and for the first time ever.
Wait, what is a middleman?
Intermediaries are central regulators, such as banks and governments, that intervene in transactions between sender and receiver. They have the power to monitor, review or roll back transactions, and they can share sensitive information they collect about you with third parties. They also often specify the financial services you can use.
Cryptocurrencies are not. Transactions connect sender and recipient directly without dealing with any central regulator. No one else has access to your funds, and no one can dictate which services you can use. This is all possible thanks to the blockchain technology that underpins the operation of digital currencies.
How is Ethereum different from Bitcoin?
Ethereum builds on the innovations of Bitcoin, launched in 2015, with some notable differences.
Both allow you to spend digital currencies without having to pay service providers or banks. But Ethereum is programmable, so you can also build and deploy decentralized applications on the Ethereum network.
Ethereum is programmable, which means that you can build specific applications that use the blockchain to store data or control your application functions. This forms a general-purpose blockchain that can be programmed to do anything. Since there are no restrictions on what Ethereum can do, great innovations can occur on the Ethereum network.
Bitcoin is just a payment network, while Ethereum is more like a marketplace for financial services, games, social networking and other applications that respect your privacy and cannot censor you.
What can Ethereum do?
What is a smart contract?
Smart contracts are computer programs that exist on the Ethereum blockchain. They are only executed when triggered by a transaction issued by a user (or other contract). Smart contracts make Ethereum extremely flexible in terms of functionality and differentiate it from other cryptocurrencies. These programs are what we now call decentralized applications or dapps.
Have you used a product whose terms of service have changed? Or removed a feature you thought would be useful? Once a smart contract is published to Ethereum, it will stay online and run as long as Ethereum exists. Even creators can't make it offline. Since smart contracts are automated, they do not discriminate against any user and are ready to use.
Common examples of smart contracts include lending apps, decentralized exchanges, insurance, crowdfunding apps — basically everything you can think of.
Ethereum community
https://ethereum.org/zh/community/