以太坊区块链最小单位是合约单位吗,以太坊最小单位是什么
答案：以太坊区块链最小单位并不是合约单位，而是以太币（Ether）。以下是相关关键词的介绍：
以太币（Ether）：以太币（Ether）是以太坊的原生代币，也是以太坊区块链最小单位，以太币是以太坊网络的基础，是用户参与以太坊的基础货币，也是以太坊系统内部的交易手续费。以太币也可以用来参与以太坊的智能合约，支付智能合约的执行费用，用户在以太坊上的所有操作都需要消耗以太币。
智能合约：智能合约是以太坊上特有的一种程序，它可以模拟真实世界的合约，通过编写智能合约，可以在以太坊网络上实现复杂的业务逻辑，它可以实现自动执行、自动确认、去中心化等功能，智能合约是以太坊的核心功能之一，也是以太坊网络上最重要的组成部分。
Gas：Gas是以太坊网络上的计算费用，也是以太坊的交易费用，用户在以太坊网络上进行的所有操作都需要付出Gas作为交易费用，Gas由以太币支付，Gas的价格由以太坊网络上的矿工自行设定，用户在以太坊网络上进行的操作越复杂，Gas的消耗也就越多，用户可以根据实际需求来设定Gas的价格和消耗量。
请查看相关英文文档
㈠ What is Ethereum
Ethereum (English: Ethereum) is an open source public blockchain platform with smart contract functions. It provides a decentralized virtual machine (called the "Ethereum Virtual Machine" EthereumVirtualMachine) through its dedicated cryptocurrency Ether (also known as "Ether") to process peer-to-peer contracts.
The token on the Fang blockchain is called Ether, code is ETH, and can be traded on the foreign exchange market of many cryptocurrencies. It is also used on Ethereum to pay transaction fees and Media for computing services.
The concept of Ethereum was first proposed by programmer Vitalik Buterin between 2013 and 2014 after being inspired by Bitcoin. It means "the next generation of cryptocurrency and decentralized application platform" and was successfully launched through ICO in 2014. Funding can begin to develop. As of February 2018, Ethereum is the second-largest cryptocurrency by market capitalization, after Bitcoin.
(1) The smallest unit of the Ethereum blockchain is the contract. Extended reading:
The Ethereum platform itself has no characteristics and no value. Similar to a programming language, it is up to entrepreneurs and developers to determine its use. But it’s clear that certain application types benefit from Ethereum’s capabilities more than others. Ethereum is particularly well-suited for applications that automate direct interactions between peers or facilitate group coordinated activities across the network.
For example, applications that coordinate peer-to-peer marketplaces or automate complex financial contracts. Bitcoin enables individuals to exchange money without resorting to other intermediaries such as financial institutions, banks or governments. Ethereum’s impact may be even more profound.
Theoretically, any complex financial activity or transaction can be coded on Ethereum automatically and reliably. In addition to financial applications, any application scenarios with high requirements on trust, security and durability - such as asset registration, voting, management and the Internet of Things - will be affected by the Ethereum platform on a large scale.
㈡ What is the role of smart contracts in blockchain technology
Smart contracts are one of the four core technologies in blockchain. This concept was first developed in 1994. It was proposed by the well-known cryptologist Nick Szabo, but due to technical and other reasons it has never been implemented. Even today, smart contracts have been used in many applications on the Internet, such as automatic repayment, drone sales, etc. , are mostly limited to smart contracts between individuals and institutions. There are almost no smart contracts between individuals. The reason is the "trust" issue. We will find that whenever we talk about contracts, most of them are strangers. This kind of need exists between strangers, and it is also related to money. What if we make an agreement without a third party as a guarantee, and I send you the money, but you break the agreement and refuse to acknowledge it? ? Therefore, smart contracts have never been popular among individuals. Later, with the emergence of blockchain,Nowadays, people have found that the blockchain is very compatible with smart energy contracts, because many characteristics of the blockchain, such as decentralization, non-tampering of data, etc., can solve the problems between strangers from a technical perspective. The issue of trust makes it possible to apply smart contracts on a large scale. The beginning of this stage is marked by the birth of Ethereum. Based on the blockchain, Ethereum applies smart contract technology. Smart contracts enable Ethereum to achieve more functions. Smart contracts are a very important application, so slowly, smart contracts have become one of the core technologies of the blockchain.
㈢ What is Ethereum/Ethereum ETH
Ethereum (ETH) is a digital token of Ethereum and is regarded as "Bitcoin version 2.0" , using the blockchain technology "Ethereum" that is different from Bitcoin, an open source public blockchain platform with smart contract results, a resonance network composed of thousands of computers around the world. Developers need to pay Ethereum (ETH) to support the operation of the application. Like other digital currencies, Ethereum can be bought and sold on trading platforms.
Warm reminder: The above explanation is for reference only and does not make any suggestions. There are risks in entering the market, so investment needs to be cautious. Before making any investment, you should ensure that you fully understand the investment nature of the product and the risks involved. After understanding and carefully evaluating the product, you can make your own judgment on whether to participate in the transaction.
Response time: 2020-12-02. For the latest business changes, please refer to the official website of Ping An Bank.
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㈣ Blockchain and smart contracts, Ethereum Developed by 183 developers, a summary of the knowledge system
A guide to the available tools, components, patterns and platforms for developing applications on Ethereum.
The creation of this list was driven by product managers at ConsenSys who saw a need for better sharing of tools, development patterns, and components between new and experienced blockchain developers.
Develop smart contracts
Smart contract language
Architecture
IDE
Other tools
< p> Test the blockchain networkTest the Ethereum faucet
Front-end Ethereum API
Back-end Ethereum API
Bootstrap/Out-of-the-Box Tools
EthereumABI (Application Binary Interface) Tools
Ethereum Client
Storage
Mahuta - IPFS storage service with additional search capabilities, formerly known as IPFS- Store
OrbitDB - Decentralized database on top of IPFS
JS IPFS API - Client library for IPFS HTTP API, implemented in JavaScript
TEMPORAL - Easy Used APIs to IPFS and other distributed/decentralized storage protocols
PINATA - The easiest way to use IPFS
Messaging
Testing tools
p>Security Tools
Monitoring
Miscellaneous Tools
Cheshire - A native sandbox implementation of the CryptoKitties API and smart contracts, available as a Truffle Box
ERCs - Ethereum Comment Request Repository
ERC-20 - Original Token Contract for Fungible Assets
ERC-721 - Order for Non-Fungible Assets Token Standard
ERC-777 - An Improved Token Standard for Fungible Assets
ERC-918 - A Mineable Token Standard
Popular Smart Contract Library< /p>
Scalability
Payment/State Channel
Plasma
Sidechain
POA Bridge
POA Bridge User Interface
POA Bridge Contract
ZK-SNARK
ZK-STARK
Pre-built UI components
The above content is from the git library:
github.com/ConsenSys/ethereum-developer-tools-list
I am Yuge, a business owner in Shenzhen A full-stack programmer, focusing on blockchain, metaverse and smart contracts, as well as additional small programs and app development.
[Prayer]
㈤ EthereumWhat is Ethereum? An introductory guide to Ethereum development
What is Ethereum? An introductory guide to Ethereum development
Many students are already eager to join the blockchain development team, but they feel unable to start. This article Based on the Ethereum platform, we will introduce various obscure concepts involved in the development of Ethereum in a popular way, and help you get started easily.
What is Ethereum
Ethereum is a decentralized application platform built on blockchain technology. It allows anyone to build and use decentralized applications running on blockchain technology within the platform.
For students who don’t understand this sentence, you can temporarily understand that Ethereum is Android in the blockchain. It is a development platform that allows us to write applications based on blockchain technology just like the Android Framework.
Before Ethereum, writing blockchain applications was like this: copy a copy of the Bitcoin code, and then change the underlying code such as encryption algorithm, consensus mechanism, network protocol, etc. (This is the case for many altcoins. A new coin will come out if you change it).
The Ethereum platform encapsulates the underlying blockchain technology, allowing blockchain application developers to develop directly based on the Ethereum platform. Developers only need to focus on the development of the application itself, thus greatly reducing the difficulty.
At present, a relatively complete development ecosystem has been formed around Ethereum: with community support, there are many development frameworks and tools to choose from.
Smart Contract
What is a Smart Contract
The program on Ethereum is called a smart contract, which is a collection of code and data (state).
Smart contracts can be understood as contracts (special transactions) written in code that can be automatically executed on the blockchain (driven by events).
In Bitcoin Script, we have mentioned that Bitcoin transactions can be programmed, but Bitcoin Script has many restrictions and the programs that can be written are also limited, while Ethereum is more complete (in computer science terms , calling it "Turing complete"), allows us to write programs (smart contracts) that can do almost anything just like any high-level language.
Smart contracts are very suitable for application scenarios that require high trust, security and durability, such as: digital currency, digital assets, voting, insurance, financial applications, prediction markets, property ownership management, Internet of Things, peer-to-peer transactions, etc. wait.
At present, apart from digital currency, there are not many real-life applications (just like the mobile platform has just begun to come out). I believe that within 1 to 3 years, various killers will slowly appear.
Programming language: Solidity
The default programming language for smart contracts is Solidity, and the file extension ends with .sol.
Solidity is a language similar to JavaScript. Use it to develop contracts and compile them into Ethereum Virtualmachine byte code.
There is also a smart contract development language that looks like Python: Serpent, but it is recommended that you still use Solidity.
Browser-Solidity is a Solidity IDE for browsers. You can click in to have a look. We will introduce more articles about the Solidity language in the future.
Operating environment: EVM
EVM (Ethereum Virtual Machine) Ethereum Virtual Machine is the operating environment for smart contracts in Ethereum.
Solidity is to EVM just like it is to JVM, so it will be easy for everyone to understand.
The Ethereum Virtual Machine is an isolated environment, and the code running inside the EVM cannot have any contact with the outside world.
The EVM runs on the Ethereum node. When we deploy the contract to the Ethereum network, the contract can run on the Ethereum network.
Contract Compilation
The Ethereum Virtual Machine runs the bytecode form of the contract, which requires us to compile the contract before deployment. You can choose Browser-Solidity Web IDE or solc compiler.
Contract deployment
When developing applications on Ethereum, the Ethereum client (wallet) is often used. Usually when we are developing, we generally do not come into contact with the concept of client or wallet. What is it?
Ethereum client (wallet)
Ethereum client, in fact, we can understand it as a developer tool, which provides account management, mining, transfer, deployment and execution of smart contracts, etc. Function.
EVM is provided by the Ethereum client.
Geth is a typical client used when developing Ethereum and is developed based on the Go language. Geth provides an interactive command console, which contains various functions (API) of Ethereum through the command console. We will introduce the use of Geth in an article later, but here everyone has a concept.
The Geth console is similar to the console in the Chrome browser developer tools, but it runs in the terminal.
Compared to Geth, Mist is an Ethereum client with a graphical operation interface.
How to deploy
The deployment of smart contracts refers to publishing the contract bytecode to the blockchain and using a specific address to identify the contract. This address is called a contract account.
There are two types of accounts in Ethereum:
· External accounts
This type of account is controlled by a private key (controlled by a person) and is not associated with any code.
·Contract Account
This type of account is controlled by their contract code and has code associated with it.
Different from Bitcoin’s UTXO design, Ethereum uses a moreSimple account concept.
Both types of accounts are the same for EVM.
The difference and relationship between external accounts and contract accounts is this: an external account can send messages to another external account or contract account by creating and signing transactions with its own private key.
Sending a message between two external accounts is the process of transferring value. But messages from the external account to the contract account activate the code of the contract account, allowing it to perform various actions (such as transferring tokens, writing to internal storage, mining a new token, performing some operations, creating a new contract, etc. wait).
Only when the external account issues instructions, the contract account will perform the corresponding operation.
Contract deployment is to deploy the compiled contract bytecode to the Ethereum blockchain in the form of sending transactions through an external account (the actual deployment is successful only after the actual miner produces the block).
Run
After the contract is deployed, when you need to call the method of this smart contract, you only need to send a message (transaction) to this contract account. After the message is triggered, the code of the smart contract will be executed in the EVM. .
Gas
Similar to cloud computing, the resources that occupy the blockchain (whether it is a simple transfer transaction or the deployment and execution of a contract) also require corresponding fees (there is no free lunch in the world, right? ).
Gas mechanism is used for billing on Ethereum. Gas can also be considered as a workload unit. The more complex the smart contract is (the number and type of calculation steps, the memory occupied, etc.), the more it requires to complete the operation. Gas.
The amount of Gas required to run the contract for any particular contract is fixed and is determined by the complexity of the contract.
The Gas price is stipulated by the person running the contract when submitting a request to run the contract to determine the fee he is willing to pay for this transaction: Gas price (denominated in Ethereum) * Gas quantity.
The purpose of Gas is to limit the amount of work required to execute a transaction while paying for execution. When the EVM executes a transaction, Gas will be gradually consumed according to specific rules. No matter where it is executed, once the Gas is exhausted, an exception will be triggered. All state modifications made in the current call frame will be rolled back. If there is Gas remaining at the end of execution, these Gas will be returned to the sending account.
Without this restriction, someone would write a contract that cannot be stopped (such as an infinite loop) to block the network.
So actually (to put the previous content together), we need an external account with an Ethereum balance to initiate a transaction (ordinary transaction or deploy and run a contract). When running, the miner charges the corresponding work Quantity fee.
Ethereum Network
Some anxious students may want to ask, how can we develop smart contracts without Ethereum? You can choose the following methods:
Select the Ethereum official website test network Testnet
In the test network, we can easily obtain free Ether coins. The disadvantage is that it takes a long time to initialize the node.
Use a private chain
Create your own Ethereum private test network, often called a private chain, which we can use as a test environment to develop, debug and test smart contracts.
With the Geth mentioned above, it is easy to create your own test network. You can mine as much Ethereum as you want without having to synchronize the entire blockchain data of the official network.
Using the Developer Network (Mode)
Compared with the private chain, under the Developer Network (Mode), a developer account with a large balance will be automatically allocated for us to use.
Use simulation environment
Another way to create a test network is to use testrpc. testrpc is an Ethereum environment simulated locally using memory. It is more convenient and faster for development and debugging. And testrpc can help us create 10 test accounts with funds at startup.
When developing a contract, you can test it in testrpc and then deploy it to the Geth node.
Update: testrpc has now been integrated into the Truffle development framework and is now named Ganache CLI.
Dapp: Decentralized Application
The Ethereum community calls applications based on smart contracts decentralized applications (DecentralizedApp). If we understand the blockchain as a database that cannot be tampered with, and smart contracts as programs that deal with the database, then it is easy to understand Dapp. A Dapp not only has smart contracts, but also needs a friendly user interface and other things.
Truffle
Truffle is a Dapp development framework. It can help us deal with a lot of trivial things, allowing us to quickly start the process of writing code - compiling - deploying - testing - packaging DApp.
Summary
Let’s summarize now. Ethereum is a platform that allows us to easily use blockchain technology to develop decentralized applications. In this application, Solidity is used to write and blockchain For interactive smart contracts, after the contract is written, we need to use the Ethereum client to deploy and run the contract with an account with balance (using the Truffle framework can better help us do these things). For the convenience of development, we can use Geth or testrpc to build a test network.
Note: In order to make it easier for everyone to understand, this article makes analogies to some concepts. Some of them are not strictly accurate. However, I also think that for beginners, it is not necessary to master every concept in detail and accurately. Learning is A gradual and in-depth process, many times we will find that after a period of time,We will have different understandings of the same thing.
㈥ What is Ethereum and what is its relationship with blockchain?
Ethereum is also a product of blockchain 2.0. It is a complete solution for open smart contracts. Bitcoin is the most important application of blockchain 1.0, completing currency and payment transactions very well. But when we need to record and transfer more complex asset types, we need a third step - a more powerful scripting system - to eventually achieve Turing completeness (the ability to run any currency, protocol and blockchain). Ethereum is a blockchain-based project that aims to provide a Turing-complete scripting language and Turing-complete platform.
Blockchain 1.0 mainly refers to Bitcoin, Blockchain 2.0 extends to all assets, and Blockchain 3.0 goes beyond currency, beyond the financial field, and even beyond the commercial field, extending to It penetrates into all aspects of our lives, including politics, social interaction, education, medical care, etc. According to the predictions and ideas of insiders, the Blockchain 3.0 era will be realized in the next five years. At that time, Blockchain will become as recognized and accepted by the public as the Internet, thus completely subverting our lives.
McKinsey & Company submitted a blockchain technology report to the U.S. Federal Insurance Advisory Committee. The report called the period from 2009 to 2016 the "Dark Age" and believed that all blockchain solutions during this period were Based on Bitcoin, the new era of blockchain will begin in 2016. By then, the application of blockchain will become unprecedentedly widespread. Applying an original sentence from the McKinsey report: Based on the current development speed of blockchain, we believe that blockchain solutions may realize their full potential in the next five years.
㈦ 108 knowledge points for getting started with blockchain
1. What is blockchain
Combine the information of multiple transactions and the information indicating the block The information is packaged and put together, and the verified package is the block.
Each block stores the hash value of the previous block, creating a relationship between blocks, that is to say, a chain. Together they are called blockchain.
2. What is Bitcoin
The concept of Bitcoin was proposed by Satoshi Nakamoto in 2009, with a total number of 21 million. The Bitcoin chain generates a block approximately every 10 minutes, and this block is mined by miners for 10 minutes. As a reward to miners, a certain number of Bitcoins will be issued to miners, but this certain number is halved every four years. Now it's 12.5. If this continues, all Bitcoins will be available in 2040.
3. What is Ethereum
The biggest difference between Ethereum and Bitcoin is the smart contract. This allows developers to develop and run various applications on it.
4. Distributed ledger
It is a database that is shared, replicated and synchronized among network members. To put it bluntly, all users on the blockchain have accounting functions and the content is consistent, which ensures that the data cannot be tampered with.
5. What is quasi-anonymity?
I believe everyone has a wallet, and the wallet address (a string of characters) used to send transactions is quasi-anonymity.
6. What is open transparency/traceability
The blockchain stores all data from history to the present, anyone can view it, and can also view any data in history.
7. What is tamper-proof
Historical data and current transaction data cannot be tampered with. The data is stored in the block on the chain and has a hash value. If the block information is modified, its hash value will also change, and the hash values of all blocks following it must also be modified to form a new chain. At the same time, the main chain is still conducting transactions to generate blocks. The modified chain must always generate blocks synchronously with the main chain to ensure that the length of the chain is the same. The cost is too high, just to modify a piece of data.
8. What is anti-DDoS attack
DDoS: Hackers control many people’s computers or mobile phones and allow them to access a website at the same time. Since the bandwidth of the server is limited, a large amount of traffic The influx of data may cause the website to fail to function properly, resulting in losses. However, the blockchain is distributed and there is no central server. If one node fails, other nodes will not be affected. Theoretically, if more than 51% of the nodes are attacked, problems will occur.
9. Definition of main chain
Taking Bitcoin as an example, at a certain point in time, a block is mined by two miners at the same time, and then 6 blocks are generated first. The chain of blocks is the main chain
10. Single chain/multi-chain
Single chain refers to the data structure that handles everything on one chain. The core essence of the multi-chain structure is composed of public chain + N sub-chains. There is only one, but in theory there can be countless sub-chains, and each sub-chain can run one or more DAPP systems
11. Public chain/alliance chain/private chain
Public Chain: Everyone can participate in the blockchain
Alliance chain: Only alliance members are allowed to participate in accounting and query
Private chain: Writing and viewing permissions are only controlled by one person In the hands of the organization.
12. Consensus layer, data layer, etc.
There are six overall structures of the blockchain: data layer, network layer, consensus layer, incentive layer, contract layer, and application layer. Data layer: a layer that records data and belongs to the underlying technology; networkNetwork layer: An architecture for building a blockchain network, which determines how users are organized. Consensus layer: Provides a set of rules to allow everyone to reach agreement on the information received and stored. Incentive layer: Design incentive policies to encourage users to participate in the blockchain ecosystem; Contract layer: Generally refers to "smart contracts", which are a set of contract systems that can be automatically executed and written according to their own needs. Application layer: Applications on the blockchain, similar to mobile apps. Former Distributed Storage R&D Center
13. Timestamp
The timestamp refers to January 1, 1970 Day 0 hours 0 minutes 0 seconds 0... The total number of seconds from the current time to now, or the total number of nanoseconds and other very large numbers. Each block is generated with a timestamp indicating when the block was generated.
14. Block/block header/block body
Block is the basic unit of blockchain, and block header and block body are components of blockchain. The information contained in the block header includes the hash of the previous block, the hash of this block, timestamp, etc. The block body is the detailed data in the block.
15. Merkle tree
Merkle tree, also called binary tree, is a data structure for storing data. The bottom layer is the original data contained in all blocks, and the upper layer is each The hash value of a block, the hash value of this layer is combined in pairs to generate a new hash value, forming a new layer, and then upwards layer by layer, until a hash value is generated. Such a structure can be used to quickly compare large amounts of data, and you can quickly find the bottom-level historical data you want without downloading all the data.
16. What is expansion?
The size of a Bitcoin block is about 1M and can save 4,000 transaction records. Expansion means making the block larger so that more data can be stored.
17. What is a chain?
Each block will save the hash of the previous block, creating a relationship between the blocks. This relationship is a chain. Data such as block transaction records and status changes are stored through this chain.
18. Block height
This is not the height mentioned in terms of distance. It refers to the total number of blocks between the block and the first block on the chain. This height indicates which block it is, and is just for identification purposes.
19. Fork
Two blocks were generated at the same time (the transaction information in the block is the same, but the hash value of the block is different), and then in Two chains are forked from these two blocks. Whoever generates 6 blocks from these two links first will be the main chain, and the other chain will be discarded.
20.Ghost Protocol
Mining pools with high computing power can easily generate blocks faster than mining machines with low computing power, resulting in most of the blocks on the blockchain being generated by these mining pools with high computing power. However, the blocks generated by mining machines with low computing power are not stored on the chain because they are slow, and these blocks will be invalid.
The ghost protocol allows blocks that should be invalidated to remain on the chain for a short time, and can also be used as part of the proof of work
. In this way, miners with small computing power will contribute more to the main chain, and large mining pools will not be able to monopolize the confirmation of new blocks.
21. Orphan blocks
As mentioned before, orphan blocks are blocks generated at the same time. One of them forms a chain, and the other does not form a chain. Then this block that does not form a chain is called an orphan block.
22. Uncle block
The orphan block mentioned above, through the ghost protocol, makes it part of the proof of work, then it will not be discarded and will be saved in the main chain superior. This block is the next
23 replay attack
The hacker resends the message that has been sent to the server. Sometimes this can deceive the server into multiple responses.
24. Directed acyclic graph
Also called data set DAG (directed acyclic graph), DAG is an ideal multi-chain data structure. Most of the blockchains mentioned now are single chains, that is, one block is connected to another block, and DAG is multiple blocks connected. The advantage is that several blocks can be generated at the same time, so the network can process a large number of transactions at the same time, and the throughput will definitely increase. However, there are many shortcomings and it is currently in the research stage.
25. What is mining
The mining process is to perform a series of conversions, connections and hash operations on the above six fields, and continue to try them one by one. The random number you are looking for, and finally successfully find a random number that meets the conditions: the value after hashing is smaller than the hash value of the preset difficulty value, then the mining is successful, and the node can broadcast the area to neighboring nodes. block, neighboring nodes receive the block and perform the same operation on the above six fields to verify compliance, and then forward it to other nodes. Other nodes also use the same algorithm to verify. If there are 51% of nodes in the entire network If all verifications are successful, even if this block is truly "mined" successfully, each node will add this block to the end of the previous block, delete the list in the block that is the same as its own record, and resurrect again. the above process. Another thing to mention is that regardless of whether the mining is successful or not, each node will pre-record the reward of 50 Bitcoins and the handling fees of all transactions (total input-total output) in the first item of the transaction list (this is " The most fundamental purpose of “mining” is alsoThe fundamental reason to ensure the long-term stable operation of the blockchain), the output address is the address of this node, but if the mining is unsuccessful, the transaction will be invalidated without any reward. Moreover, this transaction called "production transaction" does not participate in the "mining" calculation.
26. Mining machines/mining farms
Mining machines are computers with various configurations, and computing power is the biggest difference between them. A place where mining machines are concentrated in one place is a mining farm
27. Mining pool
Miners join together to form a team, and the computer group under this team is a mining pool. Mining rewards are distributed based on your own computing power contribution.
28. Mining difficulty and computing power
Mining difficulty is to ensure that the interval between generating blocks is stable within a certain short time, such as Bitcoin’s 10 minutes.
p>Block 1. Computing power is the configuration of the mining machine.
29. Verification
When verification in the blockchain is a confirmation of the legality of the transaction, each node will verify the transaction once when the transaction message is propagated between nodes. Whether the transaction is legal. For example, verify whether the syntax of the transaction is correct, whether the transaction amount is greater than 0, whether the entered transaction amount is reasonable, etc. After passing the verification, it will be packaged and handed over to the miners for mining.
30. Transaction broadcast
The node sends information to other nodes through the network.
31. Mining fees
For the blockchain to work non-stop like a perpetual motion machine, miners need to maintain the system. Therefore, the miners must be given favorable fees to make it sustainable.
32. Transaction confirmation
When a transaction occurs, the block recording the transaction will be confirmed for the first time, and will be confirmed in every area on the chain after the block. Block is reconfirmed: When the number of confirmations reaches 6 or more, the transaction is generally considered safe and difficult to tamper with.
33. Double transaction
That is, I have 10 yuan, I use the 10 yuan to buy a pack of cigarettes, and then instantly use the 10 yuan that has not yet been paid. Bought another cup of coffee. So when verifying the transaction, you need to confirm whether the 10 yuan has been spent.
34. UTXO unspent transaction output
It is a data structure containing transaction data and execution code, which can be understood as digital currency that exists but has not yet been consumed.
35. Transactions per second TPS
That is throughput, tps refers to the number of transactions the system can process per second.
36. Wallet
Similar to Alipay,For storing digital currencies, blockchain technology is more secure.
37. Cold wallet/hot wallet
A cold wallet is an offline wallet. The principle is to store it locally and use QR code communication to prevent the private key from touching the Internet. A hot wallet is an online wallet. The principle is to encrypt the private key and store it on the server. When it is needed, it is downloaded from the server and decrypted on the browser side.
38. Software Wallet/Hardware Wallet
A software wallet is a computer program. Generally speaking, a software wallet is a program that interacts with the blockchain and allows users to receive, store, and send digital currencies and can store multiple keys. Hardware wallets are smart devices that specialize in handling digital currencies.
39. Airdrop
The project sends digital currency to each user’s wallet address.
40. Mapping
Mapping is related to the issuance of blockchain currency and is a mapping between chains. For example, there are some blockchain companies that have not completed the development of the chain in the early stage. They rely on Ethereum to issue their own currency. The issuance and transactions of the early currency are all operated on Ethereum. With the development of the company, the company's own chain development has been completed. The company wants to map all the previous information on Ethereum to its own chain. This process is mapping.
41. Position
Refers to the ratio of the investor’s actual investment to the actual investment funds
42. Full position
All funds are bought Enter Bitcoin
43. Reduce the position
Sell some of the Bitcoins, but not all of them
44. Heavy positions
Compared with Bitcoin, Bitcoin accounts for a larger share of funds
45. Short position
Compared with Bitcoin, the share of funds is larger
46. Short position
Sell all the Bitcoins you hold and convert them all into funds
47. Stop loss
After obtaining a certain profit, sell the Bitcoin held to keep the profit
48. Stop loss
After losses reach a certain level, sell the Bitcoins you hold to prevent further losses
49. Bull market
Prices continue to rise and the outlook is optimistic
50. Bear market
Prices continue to fall, and the outlook is bleak
51. Bull (long)
The buyer believes that the currency price willIf the currency price rises, buy the currency, and after the currency price rises, sell it at a high price to take profits
52. Short position (short selling)
The seller believes that the currency price will fall in the future, and will hold Sell some coins (or borrow coins from the trading platform), and after the price of the currency drops, buy at a low price to take profits
53. Open a position
Buy virtual currency such as Bitcoin Currency
54. Cover the position
Buy virtual currencies such as Bitcoin in batches, such as: buy 1BTC first, then buy 1BTC later
55. Full Warehouse
Buy all the funds into a certain virtual currency at once
56. Rebound
When the currency price falls, the price rises because it falls too fast. Adjustment
57. Consolidation (sideways)
The price fluctuation is small and the currency price is stable
58. Falling
Coin The price fell slowly
59. Diving (waterfall)
The currency price fell rapidly, with a large amplitude
60. Cutting meat
Buy After Bitcoin, the price of the currency fell, and Bitcoin was sold at a loss to avoid further losses. Or after borrowing the currency to go short, the currency price rises, and then buying Bitcoin at a loss
61. Holding up
Expecting the currency price to rise, but unexpectedly the currency price falls after buying; or expecting the currency price to rise. fell, but unexpectedly, after selling, the currency price rose
62. Unwinding
After buying Bitcoin, the currency price fell, causing a temporary book loss, but then the currency price rebounded and the loss was reversed To make a profit
63. Going short
After selling Bitcoin because of the bearish market outlook, the price of the currency continued to rise, and I was unable to buy it in time, so I failed to make a profit
64. Overbought
The currency price continues to rise to a certain height, the buyer's power is basically exhausted, and the currency price is about to fall
65. Oversold
The currency price continues to fall to a certain low, the seller's power is basically exhausted, and the currency price is about to rise
66. Lure bulls
The currency price has been consolidating for a long time, and it is more likely to fall. Most of the short sellers have sold Bitcoin, and suddenly the short sellers pulled up the price of the currency, inducing the long parties to think that the price of the currency will rise and buy one after another. As a result, the short sellers suppressed the price of the currency and locked up the long parties.
67. Short-selling
After bulls buy Bitcoin, they deliberately suppress the price of the currency, making short sellers think that the price of the currency will fall, and sell them one after another. As a result, they mistakenly fall into the bullish position.Trap
68. What is NFT
The full name of NFT is "Non-Fungible Tokens", which is non-fungible tokens. In simple terms , that is, an indivisible copyright certificate on the blockchain, which is mainly used to confirm and transfer the rights of digital assets. The difference from digital currency is that it is unique and indivisible. In essence, it is a unique digital asset.
69. What is the Metaverse
The Metaverse is a collection of virtual time and space, consisting of a series of augmented reality (AR), virtual reality (VR) and the Internet (Internet) Composed of digital currency, which carries the function of value transfer in this world.
70. What is DeFi
DeFi, the full name is Decentralized Finance, which is "decentralized finance" or "distributed finance". "Decentralized finance", as opposed to traditional centralized finance, refers to various financial applications established in open decentralized networks. The goal is to establish a multi-level financial system based on blockchain technology and cryptocurrency. As a basis, re-create and improve the existing financial system
71. Who is Satoshi Nakamoto?
72. Bitcoin is different from Q Coin
Bitcoin is a decentralized digital asset with no issuing entity. Q Coin is an electronic currency issued by Tencent. It is similar to electronic points, but it is not actually a currency. Q Coin requires a centralized issuing institution. Q Coin can only be recognized and used because of the credit endorsement of Tencent. The scope of use is also limited to Tencent's games and services. The value of Q coins is entirely based on people's trust in Tencent.
Bitcoin is not issued through a centralized institution, but it is widely recognized around the world because Bitcoin can self-certify its trust. The issuance and circulation of Bitcoin are jointly accounted for by miners across the entire network, and are not A central authority is also needed to ensure that no one can tamper with the ledger.
73. What is a mining machine?
Taking Bitcoin as an example, a Bitcoin mining machine is a professional equipment that competes for accounting rights by running a large amount of calculations to obtain new Bitcoin rewards. It is generally composed of a mining chip, a heat sink and a fan, and only performs A single calculation program consumes a lot of power. Mining is actually a competition between miners for computing power. Miners with more computing power have a greater probability of mining Bitcoin. As the computing power of the entire network increases, it becomes increasingly difficult to mine bits with traditional equipment (CPU, GPU), and people have developed chips specifically for mining. The chip is the core part of the mining machine. The operation of the chip will generate a large amount of heat. In order to dissipate heat, Bitcoin mining machines are generally equipped with heat sinks and fans. User downloads Bitcoin mining on computerMining software, use this software to assign the tasks of each mining machine, and you can start mining. Each currency has a different algorithm and requires different mining machines.
74. What is quantitative trading?
Quantitative trading, sometimes also called automated trading, refers to the use of advanced mathematical models to replace human subjective judgments, which greatly reduces the impact of investor sentiment fluctuations and avoids extreme fanaticism or pessimism in the market. make irrational investment decisions. There are many types of quantitative trading, including cross-platform trading, trend trading, hedging, etc. Cross-platform trading means that when the price difference between different target platforms reaches a certain amount, sell on the platform with a higher price and buy on the platform with a lower price.
75. Blockchain asset over-the-counter trading
Over-the-counter trading is also called OTC trading. Users need to find their own counterparties and do not need to match the transaction. The transaction price is determined by negotiation between the two parties. The two parties can fully communicate through face-to-face negotiation or telephone communication.
76. What is a timestamp?
The blockchain ensures that each block is connected sequentially through timestamps. Timestamps enable every piece of data on the blockchain to have a time stamp. Simply put, timestamps prove when something happened on the blockchain and cannot be tampered with by anyone.
77. What is a blockchain fork?
Upgrading software in a centralized system is very simple, just click "Upgrade" in the app store. However, in decentralized systems such as blockchain, "upgrading" is not that simple, and a disagreement may even cause a blockchain fork. Simply put, a fork refers to a disagreement when the blockchain is "upgraded", resulting in a fork in the blockchain. Because there is no centralized organization, every code upgrade of digital assets such as Bitcoin needs to be unanimously recognized by the Bitcoin community. If the Bitcoin community cannot reach an agreement, the blockchain is likely to form a fork.
78. Soft fork and hard fork
Hard fork means that when the Bitcoin code changes, the old nodes refuse to accept the blocks created by the new nodes. Blocks that do not comply with the original rules will be ignored, and miners will follow the original rules and create new blocks after the last block they verified. A soft fork means that old nodes are not aware of the changes to the Bitcoin code and continue to accept blocks created by new nodes. Miners may work on blocks they have no understanding of, or validation of. Both soft forks and hard forks are "backwards compatible" to ensure that new nodes can verify the blockchain from scratch. Backward compatibility means that new software accepts data or code generated by old software. For example, Windows 10 can run Windows XP applications. Soft forks can also be "forward compatible".
79. Blockchain project classification and application
FromJudging from the current mainstream blockchain projects, blockchain projects are mainly divided into four categories: Category 1: Currency; Category 2: Platform; Category 3: Application; Category 4: Asset Tokenization.
80. USDT against the US dollar
USDT is Tether USD, a token launched by Tether that is against the US dollar (USD). 1USDT=1 US dollar, users can use USDT and USD for 1:1 exchange at any time. Tether implements a 1:1 reserve guarantee system, that is, each USDT token will have a reserve guarantee of 1 US dollar, which supports the stability of the USDT price. The unit price of a certain digital asset is USDT, which is equivalent to its unit price in US dollars (USD).
81. Altcoins and alternative coins
Altcoins refer to blockchain assets that use the Bitcoin code as a template and make some modifications to its underlying technology blockchain, among which Those with technological innovations or improvements are also called alternative coins. Because the Bitcoin code is open source, the cost of plagiarism in Bitcoin is very low. You can even generate a brand new blockchain by simply copying the Bitcoin code and modifying some parameters.
82. Three major exchanges
Binance: https://accounts.binancezh.ac/zh-CN
Okex: https://www .ouyi.top/
Huobi: https://www.huobi.af/zh-cn
83. Market software
Mytoken: http: //www.mytoken.com/
Non-small account: https://www.feixiaohao.co/
84. Information website
Babbitt: https://www.8btc.cn
Golden Finance: http://www.jinse.com/
Coin World News: http://www.bishijie.com < /p>
85. Blockchain Explorer
BTC: https://btc.com/
ETH: https://etherscan.io/
BCH: https://blockchair.com/bitcoin-cash/blocks
LTC: http://www.qukuai.com/search/ltc
ETC: https://gastracker.io/
86. Wallet
Imtoken: https://imatoken.net/
Bitpie: https://bitpie.com/
87. Decentralized Exchange
uniswap: https://uniswap.org
< p>88. NFT Exchange
Opensea: https://opensea.io
Super Rare: https://superrare. com/
89. Ladder
Bring your own, buy a reliable ladder
90. Platform currency
The digital currency issued by the platform, Used to deduct handling fees, transactions, etc.
91. Bull market, bear market
Bull market: rising market
Bear market: falling market
92. Blockchain 1.0
A currency trading system based on distributed ledgers, represented by Bitcoin
93. Blockchain 2.0
Ethereum (intelligent Contract blockchain technology represented by contract) is 2.0
94. Blockchain 3.0
In the era of intelligent Internet of Things, it goes beyond the financial field to provide decentralized solutions for various industries Solution
95. Smart Contract
Smart Contract is a computer protocol designed to spread, verify or execute contracts in an information-based way. Simply put, electronic contracts are determined in advance. Once the contract is confirmed by both parties, the contract will be automatically executed.
96. What is a token?
The token economy is an economic system with Token as the only reference standard, which is equivalent to a pass. If you own Token, you have rights and interests, and you have the right to speak.
Big data is the means of production, AI is the new productivity, and blockchain is the new production relationship. Big data refers to a collection of data that cannot be captured, managed and processed within a certain time range using conventional software tools. It requires new processing models to have stronger decision-making power, insight discovery and process optimization capabilities.Huge amount of power, high growth rate and diversified information assets. Simply understood, big data is massive data accumulated over a long period of time and cannot be obtained in the short term. Blockchain can be used as a way to obtain big data, but it cannot replace big data. Big data is only used as a medium running in the blockchain and has no absolute technical performance, so the two cannot be confused. (The production relationship is simply understood as the labor exchange and consumption relationship. The core lies in productivity, and the core of productivity lies in production tools)
ICO, Initial Coin Offering, initial public token issuance, is the first step in the blockchain digital currency industry. Crowdfunding. It is the most popular topic and investment trend in 2017, and the country launched a regulatory plan on September 4. Speaking of ICO, people will think of IPO, and the two are essentially different.
99. Five characteristics of digital currency
The first characteristic: decentralization
The second characteristic: having open source code
The third feature: independent electronic wallet
The fourth feature: constant issuance
The fifth feature: global circulation
100. What is decentralization?
It has no issuer, does not belong to any institution or country, and is a publicly issued currency designed, developed and stored on the Internet by Internet network experts.
100. What is measurement (scarcity)?
Once the total amount of issuance is set, it is permanently fixed, cannot be changed, cannot be over-issued at will, and is subject to global Internet supervision. Because the difficulty of mining and mining changes over time, the longer the time, the greater the difficulty of mining, and the fewer coins are mined, so it is scarce.
101. What is open source code?
The alphanumeric code is stored on the Internet. Anyone can find out the source code of its design, everyone can participate, can mine it, and it is open to the world.
102. What is anonymous transaction? Private wallet private?
Everyone can register and download the wallet online without real-name authentication. It is completely composed of encrypted digital codes. It can be sent and traded globally in real-time point-to-point without resorting to banks or any institutions. It cannot be traced by anyone without my authorization. ,Inquire.
A contract transaction refers to an agreement between a buyer and seller to receive a certain amount of an asset at a specified price at a certain time in the future. The objects of contract trading are standardized contracts formulated by the exchange. The exchange stipulates standardized information such as commodity type, transaction time, quantity, etc. A contract represents the rights and obligations of the buyer and seller.
105. Digital Currency Industry Chain
Chip manufacturers, mining machine manufacturers, and mining machines act as agents for mining and mining to exchanges for retail investors to speculate in coins
106. Who is Erben?
Erben: Digital Currency Value Investor
Investment style: Steady
Building a community: Erben’s Miscellaneous Talk (high-quality price investment community)
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107. Two investment strategies
Combining long and short term, focusing on price investment, no contracts, no short-term play
Reasonable layout, scientific operation, prudent and conservative, making periodic money
108. Two books?
Welcome currency friends and seek common development
