Ethereum smart contract

2. Smart contract & quot The term "smart contract" can be traced back to at least 1995 and was proposed by the prolific interdisciplinary legal scholar Nick Szabo. He mentioned the concept of smart contract in several articles published on his website. His definition is as follows:
& quot; A smart contract is a set of promises defined in digital form, including the agreements on which the contract participants can execute these promises& quot;
let's explore the meaning of his definition in more detail
commitment
a set of commitments refers to the (often mutual) rights and obligations agreed by contract participants. These commitments define the nature and purpose of the contract. Take a sales contract as a typical example. The seller promises to deliver the goods and the buyer promises to pay a reasonable price
digital form
digital form means that contracts have to be written into computer-readable code. This is necessary, because as long as the participants reach an agreement, the rights and obligations of smart contract establishment are executed by a computer or computer network
to further explain:
(1) when will the parties to the smart contract reach an agreement? The answer depends on the specific smart contract implementation. Generally speaking, the contract is discovered when the parties are committed to the execution of the contract by installing the contract on the contract host platform< (2) contract execution
& quot; Execute & quot; And the real meaning of it also depends on implementation. Generally speaking, implementation means active implementation through technical means
(3) computer readable code
in addition, the contract needs specific & quot; Digital form & quot; Very much depends on the agreement that the parties agree to use
protocol
protocol is technical implementation, on this basis, the contract commitment is realized, or the contract commitment is recorded. Which agreement to choose depends on many factors, the most important of which is the nature of the assets being traded ring the performance of the contract
take the sales contract as an example. Suppose that the participants agree to pay in bitcoin. The chosen protocol will obviously be bitcoin protocol, on which the smart contract will be implemented. Therefore, the contract must use & quot; Digital form & quot; It's bitcoin scripting language. Bitcoin scripting language is a non Turing complete, imperative, stack based programming language, similar to forth.

3. The program running on the blockchain is usually called smart contract. So we usually change the name of writing blockchain program to writing smart contract
although bitcoin can also write smart contracts, the syntax supported by bitcoin is only related to transactions, and there are limited things it can do
therefore, when it comes to writing smart contracts, it usually refers to Ethereum blockchain that supports the execution of Turing complete programs.

4.

The smart contract has been written for a long time

if they can add changes, the description is centralized

the contract is written into the Ethereum smart contract, which is a contradiction sentence

the financial customer service doesn't understand, which is very unreliable

community sites

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6. Ethereum project draws lessons from the technology of bitcoin blockchain and expands its application scope. If bitcoin is a special calculator using blockchain technology, Ethereum is a general-purpose computer using blockchain technology. In short, Ethereum = blockchain + smart contract
compared with bitcoin, the biggest difference of Ethereum is that it can support a more powerful scripting language (technically speaking, Turing's complete scripting language), allowing developers to develop any application and implement any smart contract on it, which is also the most powerful point of Ethereum. As a platform, Ethereum can be compared with Apple's app store, on which any developer can develop applications and sell them to users. Each type of financial contract can be written as a smart contract in the form of program code<

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7. Ethereum is a distributed computing platform. It generates an cryptocurrency called ether. Programmers can write "smart contracts" on the Ethereum blockchain, and these Ethereum smart contracts will be executed automatically according to the code

what is Ethereum
Ethereum is often compared with bitcoin, but the situation is different. Bitcoin is a kind of cryptocurrency and distributed payment network, which allows bitcoin to be transferred between users

related: what is bitcoin? How does it work

Ethereum has a bigger goal. As Ethereum says, "Ethereum is a distributed platform running smart contracts.". These smart contracts run on "Ethereum virtual machine", a distributed computing network composed of all devices running Ethernet nodes

"distributed platform" means that anyone can set up and run an Ethereum node just as anyone can run a bitcoin node. Anyone who wants to run "smart contracts" on nodes must pay the operators of these nodes in ether, which is a cryptocurrency related to Ethereum. Therefore, the person running the Ethernet node provides computing power and gets paid in the Ethernet, which is similar to the way that the person running the bitcoin node provides hash power and pays in bitcoin

in other words, although bitcoin is only a blockchain and payment network, Ethereum is a distributed computing network, and its blockchain can be used for many other things. Details are provided in the Ethereum white paper

what is ether
Ethernet is a digital token (or cryptocurrency) related to Ethereum blockchain. In other words, Ethereum is the token and Ethereum is the platform. But now people often use these terms alternately. For example, coinbase allows you to buy Ethereum, which stands for Ethereum

this is technically "altcoin", which actually means a non bitcoin cryptocurrency. Like bitcoin, ether is supported by distributed blockchain - in this case, Ethereum blockchain

developers who want to create applications or Ethereum smart contracts on Ethereum blockchain need Ethernet token to pay for nodes to host it, while users of Ethereum based applications may need Ethernet to pay for services in these applications. People can also sell services outside the Ethereum network and accept Ethernet payments, or they can sell Ethernet tokens in cash - just like bitcoin

9. Bitcoin is not supported, only point-to-point transmission is allowed