DAPP是DecentralizedApplication的缩写，译为:分散式的应用程序。DAPP是一种互联网应用程序，与传统的APP最大的区别是：DAPP运行在去中心化的网络上，也就是区块链网络中。网络中不存在中心化的节点可以完整的控制DAPP。
What is a smart contract?
Smart contract is actually a piece of code running in the Ethereum network.Its biggest feature is that it is automatically executed and cannot be changed once deployed.This feature of smart contract ensures that all functions written in the contract can be executed logically.After Ethereum deploys the smart contract,it means that it has a degree of never disappearing and automatic execution,and can interact with the network contract at any time.A smart contract is similar to the TCP/IP protocol in the Internet.The transmission and operation of the network completely follow the protocol standards.
DAPP与智能合约
以太坊中一般会认为智能合约就是DAPP，当然更准确的可以认为智能合约相当于服务器后台，另外要实现用户体验，还需要UI交互界面，通过RPC与后台对接，那么DAPP就是包含完整的智能合约+用户UI交互界面。
区块链相对于DAPP来说是应用运行的底层环境。简单的可以类比为IOS，Android等手机操作系统于运行与之上的各种App。
一个完全的DAPP是需要满足完全开源并且是自治的应用程序。DAPP一经部署完毕，，便不可更改。应用的升级必须由大部分用户达成共识之后才可以进行升级。所有的数据必须进行加密存储在去中心化的区块链应用平台上。其次DAPP必须要有token机制。区块链DAPP能够进行容错，不会出现单点故障。它们没有中心化的机构能够进行干扰。不会出现某些数据的删除或者修改。甚至不能被关闭。
Ethereum is a blockchain application development platform.Based on the network and smart contract language built by Ethereum,we can realize various distributed applications(DApp)that are close to the real world
什么是DAPP？
DApp是Decentralized Application的缩写，译为:分散式的应用程序。App我们都知道，我们在智能手机上安装的应用程序也就是App。而DApp它的意思就是分散式的应用程序或去中心化的应用程序。
DApp与传统的App最大的区别是：DApp运行在去中心化的网络上，也就是区块链网络中。网络中不存在中心化的节点可以完整的控制DApp。而App我们都知道，是中心化的，需要在中心化的服务器上来获取数据，处理数据。DAPP运用区块链的底层技术开发平台，就好比手机的IOS系统和Android系统，是各DAPP的底层生态环境。也是区块链世界中的基础服务提供方。
A part of the blockchain is a decentralized distributed ledger.Each block is stored in the distributed ledger,and transactions can be publicly verified.It allows anonymous blockchain applications to execute transactions to obtain transactions occurring on the blockchain(such as settlement).Data records running on these blockchains will be stored in blocks.Only users can access the data on the blockchain in a secure way to associate it with the correct transaction and cannot forge or tamper with the data.
