英文地址： http://hyperledger-fabric.readthedocs.io/en/latest/key_concepts.html#
Key Concepts/关键概念
- Introduction/ 介绍
- Hyperledger Fabric Functionalities/Hyperledger Fabric 功能列表
- Hyperledger Fabric Model/ Hyperledger Fabric 模型
- Identity/ 身份标识
- Membership/ 成员关系
- Peers
- Ledger/账本
- Use Cases/用例
英文原文地址：http://hyperledger-fabric.readthedocs.io/en/latest/blockchain.html
Introduction/介绍
Hyperledger Fabric is a platform for distributed ledger solutions underpinned by a modular architecture delivering high degrees of confidentiality, resiliency, flexibility, and scalability. It is designed to support pluggable implementations of different components and accommodate the complexity and intricacies that exist across the economic ecosystem.
Hyperledger Fabric是分布式账本解决方案的平台，支持模块化架构，提供高度的机密性，弹性，灵活性和可扩展性。 它旨在支持不同组件的可插拔实现，并适应经济生态系统中存在的复杂性和复杂性。
We recommend first-time users begin by going through the rest of the introduction below in order to gain familiarity with how blockchains work and with the specific features and components of Hyperledger Fabric.
我们建议初次使用者首先阅读下面介绍的其余部分，以便熟悉区块链的工作方式以及Hyperledger Fabric的特定功能和组件。
Once comfortable — or if you’re already familiar with blockchain and Hyperledger Fabric — go to Getting Started and from there explore the demos, technical specifications, APIs, etc.
一旦合适 - 或者您已经熟悉区块链和Hyperledger Fabric--转到入门，并从那里探索演示，技术规范，API等。
What is a Blockchain?/区块链是什么？
A Distributed Ledger/分布式帐簿
At the heart of a blockchain network is a distributed ledger that records all the transactions that take place on the network.
区块链网络的核心是一个分布式账本，用于记录在网络上发生的所有交易。
A blockchain ledger is often described as decentralized because it is replicated across many network participants, each of whom collaborate in its maintenance. We’ll see that decentralization and collaboration are powerful attributes that mirror the way businesses exchange goods and services in the real world.
区块链总账通常被描述为去中心化的，因为它被复制到许多网络参与者中，每个参与者都在协作维护。 我们将看到，分权和协作是反映企业在现实世界中交换产品和服务方式的强大属性。
In addition to being decentralized and collaborative, the information recorded to a blockchain is append-only, using cryptographic techniques that guarantee that once a transaction has been added to the ledger it cannot be modified. This property of “immutability” makes it simple to determine the provenance of information because participants can be sure information has not been changed after the fact. It’s why blockchains are sometimes described as systems of proof.
除了去中心化和协作之外，记录在区块链中的信息只能追加，使用加密技术可保证一旦交易已添加到总账中，便无法对其进行修改。 这种“不变性”的特性使得确定信息的来源变得简单，因为参与者可以肯定信息在事后没有发生改变。 这就是区块链有时被描述为证明体系的原因。
Smart Contracts/智能合约
To support the consistent update of information — and to enable a whole host of ledger functions (transacting, querying, etc) — a blockchain network uses smart contracts to provide controlled access to the ledger.
为了支持信息更新的一致性 - 并启用一整套总账功能（如交易，查询等） - 区块链网络使用智能合约来提供对总账的受控访问。
Smart contracts are not only a key mechanism for encapsulating information and keeping it simple across the network, they can also be written to allow participants to execute certain aspects of transactions automatically.
智能合约不仅是封装信息并在整个网络中保持简单传递信息的关键机制，还可以编写它们以允许参与者自动执行交易的某些方面。
A smart contract can, for example, be written to stipulate the cost of shipping an item where the shipping charge changes depending on how quickly the item arrives. With the terms agreed to by both parties and written to the ledger, the appropriate funds change hands automatically when the item is received.
例如，可以写一份智能合约来规定运输费用根据物品到达的速度而变化的运输费用。 根据双方同意并写入总账的条款，当条款中的条件满足时，适当的资金会自动转手。
Consensus/共识
The process of keeping the ledger transactions synchronized across the network — to ensure that ledgers update only when transactions are approved by the appropriate participants, and that when ledgers do update, they update with the same transactions in the same order — is called consensus.
在整个网络中保持总账交易同步的过程 - 确保总账仅在交易获得适当参与者批准时才更新，并且当总账确实更新时，他们以相同的顺序更新相同的交易 - 称为共识。
You’ll learn a lot more about ledgers, smart contracts and consensus later. For now, it’s enough to think of a blockchain as a shared, replicated transaction system which is updated via smart contracts and kept consistently synchronized through a collaborative process called consensus.
您将在后面学到更多关于总账，智能合约和共识的知识。 就目前而言，将区块链视为共享的，复制的交易系统就足够了，该交易系统通过智能合约进行更新，并通过一个协作过程（称为共识）保持同步一致。
Why is a Blockchain useful?/为什么区块链有用？
Today’s Systems of Record
当今的记录系统
The transactional networks of today are little more than slightly updated versions of networks that have existed since business records have been kept. The members of a business network transact with each other, but they maintain separate records of their transactions. And the things they’re transacting — whether it’s Flemish tapestries in the 16th century or the securities of today — must have their provenance established each time they’re sold to ensure that the business selling an item possesses a chain of title verifying their ownership of it.
今天的交易网络仅仅是自业务记录以来存在的略微更新的网络版本。 一个商业网络的成员彼此进行交易，但他们维护着他们交易的单独记录。 而且他们正在进行的交易 - 无论是16世纪的佛兰芒挂毯还是今日的证券 - 每次出售时都必须确立出处，以确保出售商品的商家拥有一系列所有权，以验证其所有权 它。
What you’re left with is a business network that looks like this:
Modern technology has taken this process from stone tablets and paper folders to hard drives and cloud platforms, but the underlying structure is the same. Unified systems for managing the identity of network participants do not exist, establishing provenance is so laborious it takes days to clear securities transactions (the world volume of which is numbered in the many trillions of dollars), contracts must be signed and executed manually, and every database in the system contains unique information and therefore represents a single point of failure.
现代技术已经从石板和纸质文件夹发展到硬盘驱动器和云平台，但是其基本结构是相同的。 用于管理网络参与者身份的统一系统是不存在的，确立起源非常繁琐，需要数天的时间才能明确证券交易（其世界交易量的数量为数万亿美元），合同必须手动签署和执行，并且系统中的每个数据库都包含唯一的信息，因此意味着存在单点故障。
It’s impossible with today’s fractured approach to information and process sharing to build a system of record that spans a business network, even though the needs of visibility and trust are clear.
尽管可见性和信任度的需求是明确的，但今天关于信息和流程分享的繁杂（破碎）的方法仍然不可能建立一个跨越商业网络的记录系统。
The Blockchain Difference/区块链差异
What if, instead of the rat’s nest of inefficiencies represented by the “modern” system of transactions, business networks had standard methods for establishing identity on the network, executing transactions, and storing data? What if establishing the provenance of an asset could be determined by looking through a list of transactions that, once written, cannot be changed, and can therefore be trusted?
如果不是由“现代”交易系统所代表的低效率的老鼠窝，那么业务网络是否具有在网络上建立身份，执行交易和存储数据的标准方法？ 如果确定资产的出处可以通过查看交易清单而确认，这种交易一旦写入，就不能改变，那么资产出处因此就该信任吗？
That business network would look more like this:
该业务网络看起来更像这样：
This is a blockchain network, wherein every participant has their own replicated copy of the ledger. In addition to ledger information being shared, the processes which update the ledger are also shared. Unlike today’s systems, where a participant’s private programs are used to update their private ledgers, a blockchain system has shared programs to update shared ledgers.
这是一个区块链网络，每个参与者都有自己的账本副本。 除了共享总账信息之外，更新账本的过程也是共享的。 与今天的系统不同，在参与者使用私人程序来更新他们的私人账本时，区块链系统使用共享程序来更新共享总账。
With the ability to coordinate their business network through a shared ledger, blockchain networks can reduce the time, cost, and risk associated with private information and processing while improving trust and visibility.
凭借通过共享总账协调业务网络的能力，区块链网络可以减少与私人信息和处理相关的时间，成本和风险，同时提高信任度和可视性。
You now know what blockchain is and why it’s useful. There are a lot of other details that are important, but they all relate to these fundamental ideas of the sharing of information and processes.
您现在知道区块链是什么以及它为什么有用。 还有很多其他重要的细节，但都涉及到信息和流程共享的基本思想。
What is Hyperledger Fabric?/Hyperledger Fabric是什么？
The Linux Foundation founded the Hyperledger project in 2015 to advance cross-industry blockchain technologies. Rather than declaring a single blockchain standard, it encourages a collaborative approach to developing blockchain technologies via a community process, with intellectual property rights that encourage open development and the adoption of key standards over time.
Linux基金会在2015年创立了Hyperledger项目，以推进跨行业区块链技术。它不是宣布
单一的区块链标准，而是鼓励通过社区进程，采用协作的方法开发区块链技术，鼓励开放式发展的知识产权和随着时间的推移采用关键标准
Hyperledger Fabric is one of the blockchain projects within Hyperledger. Like other blockchain technologies, it has a ledger, uses smart contracts, and is a system by which participants manage their transactions.
Hyperledger Fabric是Hyperledger中的区块链项目之一。像其他区块链技术一样，它具有总账，使用智能合约，是一个参与者管理其交易的系统。
Where Hyperledger Fabric breaks from some other blockchain systems is that it is private and permissioned. Rather than an open permissionless system that allows unknown identities to participate in the network (requiring protocols like “proof of work” to validate transactions and secure the network), the members of a Hyperledger Fabric network enroll through a trusted Membership Service Provider (MSP).
Hyperledger Fabric从其他一些区块链系统中解脱出来的地方在于它是私有的并且是带许可授权的。 不像一个开放无需许可授权的网络--允许未知身份者加入网络（需要像“工作证明”这样的协议来验证交易和保护网络），Hyperledger Fabric网络的成员可通过一个可信的成员资格服务提供商（MSP）注册加入网络 。
Hyperledger Fabric also offers several pluggable options. Ledger data can be stored in multiple formats, consensus mechanisms can be swapped in and out, and different MSPs are supported.
Hyperledger Fabric还提供多种可插拔选项。 总帐数据可以以多种格式存储，共识机制可以在打开和关闭间切换，并支持不同的MSP。
Hyperledger Fabric also offers the ability to create channels, allowing a group of participants to create a separate ledger of transactions. This is an especially important option for networks where some participants might be competitors and not want every transaction they make — a special price they’re offering to some participants and not others, for example — known to every participant. If two participants form a channel, then those participants — and no others — have copies of the ledger for that channel.
Hyperledger Fabric还提供创建管道(channel)的能力，允许一组参与者创建单独的交易总账。 这对于网络来说是一个特别重要的选项，尤其是网络中的部分参与者是竞争关系时，对于他们进行的每一笔交易--例如，们向某些参与者提供的特殊价格--他们不希望每位参与者都知道。 如果两个参与者来自于同一个管道(channel)，那么这些参与者（而不是其他人）就拥有该管道(channel)的总账副本。
Shared Ledger/共享总账
Hyperledger Fabric has a ledger subsystem comprising two components: the world state and the transaction log. Each participant has a copy of the ledger to every Hyperledger Fabric network they belong to.
Hyperledger Fabric具有由两个组件构成的总账子系统：世界状态和交易日志。 每个参与者都有一个总账的副本--对应于所属的每个Hyperledger Fabric网络。
The world state component describes the state of the ledger at a given point in time. It’s the database of the ledger. The transaction log component records all transactions which have resulted in the current value of the world state; it’s the update history for the world state. The ledger, then, is a combination of the world state database and the transaction log history.
世界状态组件描述了在给定时间点的总账的状态。 这是总账的数据库。 交易日志组件记录产生当前世界状态的值的所有交易; 这是世界状态的更新历史。 于是，总账是世界状态数据库和历史交易日志记录的组合。
The ledger has a replaceable data store for the world state. By default, this is a LevelDB key-value store database. The transaction log does not need to be pluggable. It simply records the before and after values of the ledger database being used by the blockchain network.
总账拥有可替换的世界状态数据存储。 默认情况下，这是一个LevelDB键值存储数据库。 交易日志不需要是可插入的。 它只是记录区块链网络使用的总账数据库使用的前后值。
Smart Contracts/智能合约
Hyperledger Fabric smart contracts are written in chaincode and are invoked by an application external to the blockchain when that application needs to interact with the ledger. In most cases, chaincode interacts only with the database component of the ledger, the world state (querying it, for example), and not the transaction log.
Chaincode can be implemented in several programming languages. Currently, Go and Node are supported.
Hyperledger Fabric智能合约以链码形式编写，并在应用程序需要与总账进行交互时由区块链外部的应用程序调用。在绝大多数情况下，链码仅与总账的数据库组件（世界状态）（例如查询）交互，而不与交易日志交互。
Chaincode可以用几种编程语言实现。目前，支持Go和Node。
Privacy/隐私
Depending on the needs of a network, participants in a Business-to-Business (B2B) network might be extremely sensitive about how much information they share. For other networks, privacy will not be a top concern.
Hyperledger Fabric supports networks where privacy (using channels) is a key operational requirement as well as networks that are comparatively open.
根据网络的需求，企业对企业（B2B）网络的参与者可能会对他们共享的信息量非常敏感。对于其他网络而言，隐私不会成为首要问题。
Hyperledger Fabric支持网络隐私（使用管道）和相对开放是关键运行需求。
Consensus/共识
Transactions must be written to the ledger in the order in which they occur, even though they might be between different sets of participants within the network. For this to happen, the order of transactions must be established and a method for rejecting bad transactions that have been inserted into the ledger in error (or maliciously) must be put into place.
交易必须按照发生的顺序写入总账，尽管它们可能位于网络中不同的参与者之间。要保证如此，必须建立交易顺序，并且必须实施一种方法，用于拒绝错误（或恶意）插入总账的不良交易。
This is a thoroughly researched area of computer science, and there are many ways to achieve it, each with different trade-offs. For example, PBFT (Practical Byzantine Fault Tolerance) can provide a mechanism for file replicas to communicate with each other to keep each copy consistent, even in the event of corruption. Alternatively, in Bitcoin, ordering happens through a process called mining where competing computers race to solve a cryptographic puzzle which defines the order that all processes subsequently build upon.
这是一个经过深入研究的计算机科学领域，有很多方法可以实现它，每个方法都有不同的权衡。例如，PBFT（实用拜占庭容错）可以提供文件副本相互通信的机制，以保持每个副本的一致性，即使在发生损坏的情况下也是如此。或者，在比特币中，通过称为挖掘的过程进行排序，竞争的计算机竞相解决加密难题，该加密难题定义所有进程随后建立的顺序。
Hyperledger Fabric has been designed to allow network starters to choose a consensus mechanism that best represents the relationships that exist between participants. As with privacy, there is a spectrum of needs; from networks that are highly structured in their relationships to those that are more peer-to-peer.
Hyperledger Fabric被设计为允许网络初始者选择最能代表参与者之间存在关系的共识机制。与隐私一样，还有一系列需求;从关系高度结构化的网络到更多peer-to-peer的网络。
We’ll learn more about the Hyperledger Fabric consensus mechanisms, which currently include SOLO and Kafka.
我们将进一步了解Hyperledger Fabric共识机制，其中包括SOLO和Kafka。
Where can I learn more?
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Identity (conceptual documentation)
A conceptual doc that will take you through the critical role identities play in a Fabric network (using an established PKI structure and x.509 certificates).
一个概念性文档，可以帮助您了解Fabric网络中的关键角色身份（使用已建立的PKI结构和x.509证书）。
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Membership (conceptual documentation)
Talks through the role of a Membership Service Provider (MSP), which converts identities into roles in a Fabric network.
通过会员服务提供商（MSP）的角色进行谈话，该服务提供商将身份转换为Fabric网络中的角色。
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Peers (conceptual documentation)
Peers — owned by organizations — host the ledger and smart contracts and make up the physical structure of a Fabric network.
Peers（概念文件）
Peers--由机构所有 - 承载总账和智能合约，并构成Fabric网络的物理结构。
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Building Your First Network (tutorial)/ 建立你的第一个网络（教程）
Learn how to download Fabric binaries and bootstrap your own sample network with a sample script. Then tear down the network and learn how it was constructed one step at a time.
了解如何下载Fabric二进制文件并使用示例脚本引导您自己的示例网络。然后分解网络并了解它是如何一次构建的。
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Writing Your First Application (tutorial)/ 编写第一个应用程序（教程）
Deploys a very simple network — even simpler than Build Your First Network — to use with a simple smart contract and application.
部署一个非常简单的网络 - 比构建您的第一个网络更简单 - 与简单的智能合约和应用程序配合使用。
A high level look look at a sample transaction flow.
高层次的视角观看一个示例交易流程。
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Hyperledger Fabric Model/Hyperledger Fabric模型
A high level look at some of components and concepts brought up in this introduction as well as a few others and describes how they work together in a sample transaction flow.
从高层次视角着眼于本文介绍中引入的一些组件和概念以及其他几个组件，并描述它们如何在示例事务流中一起工作的。