什么是云計算?

葛嬌嬌

Simply put， cloud computing is the delivery of computing services—including servers， storage， databases， networking， software， analytics， and intelligence—over the Internet （“the cloud”） to offer faster innovation， flexible resources， and economies of scale. You typically pay only for cloud services you use， helping lower your operating costs， run your infrastructure more efficiently and scale1 as your business needs change.

Top benefits of cloud computing

Cloud computing is a big shift from the traditional way businesses think about IT resources. Here are seven common reasons organisations are turning to cloud computing services：

Cost

Cloud computing eliminates the capital expense of buying hardware and software and setting up and running on-site2 datacenters—the racks of servers， the round-the-clock electricity for power and cooling， the IT experts for managing the infrastructure. It adds up fast.

Speed

Most cloud computing services are provided self service and on demand， so even vast amounts of computing resources can be provisioned in minutes， typically with just a few mouse clicks， giving businesses a lot of flexibility and taking the pressure off capacity planning.

Global scale

The benefits of cloud computing services include the ability to scale elastically. In cloud speak3， that means delivering the right amount of IT resources—for example， more or less computing power， storage， bandwidth—right when it is needed and from the right geographic location.

Productivity

On-site datacenters typically require a lot of “racking and stacking4”— hardware setup， software patching， and other time-consuming IT management chores. Cloud computing removes the need for many of these tasks， so IT teams can spend time on achieving more important business goals.

Performance

The biggest cloud computing services run on a worldwide network of secure datacenters， which are regularly upgraded to the latest generation of fast and efficient computing hardware. This offers several benefits over a single corporate datacenter， including reduced network latency for applications and greater economies of scale.

Reliability

Cloud computing makes data backup， disaster recovery and business continuity easier and less expensive because data can be mirrored5 at multiple redundant sites on the cloud providers network.

Security

Many cloud providers offer a broad set of policies， technologies and controls that strengthen your security posture overall， helping protect your data， apps and infrastructure from potential threats.

Types of cloud computing

There are three different ways to deploy cloud services： on a public cloud， private cloud or hybrid cloud.

Public cloud

Public clouds are owned and operated by a third-party cloud service providers， which deliver their computing resources like servers and storage over the Internet. Microsoft Azure6 is an example of a public cloud. With a public cloud， all hardware， software and other supporting infrastructure is owned and managed by the cloud provider. You access these services and manage your account using a web browser.

Private cloud

A private cloud refers to cloud computing resources used exclusively by a single business or organisation. A private cloud can be physically located on the companys on-site datacenter. Some companies also pay third-party service providers to host their private cloud. A private cloud is one in which the services and infrastructure are maintained on a private network.

Hybrid cloud

Hybrid clouds combine public and private clouds， bound together by technology that allows data and applications to be shared between them. By allowing data and applications to move between private and public clouds， a hybrid cloud gives your business greater flexibility， more deployment options and helps optimise your existing infrastructure， security and compliance.

Types of cloud services： IaaS， PaaS， serverless and SaaS

Most cloud computing services fall into four broad categories： infrastructure as a service （IaaS）， platform as a service （PaaS）， serverless and software as a service （SaaS）. These are sometimes called the cloud computing stack because they build on top of one another.

Infrastructure as a service （IaaS）

This is the most basic category of cloud computing services. With IaaS， you rent IT infrastructure—servers and virtual machines （VMs）， storage， networks， operating systems—from a cloud provider on a pay-as-you-go basis.

Platform as a service （PaaS）

Platform as a service refers to cloud computing services that supply an on-demand environment for developing， testing， delivering and managing software applications. PaaS is designed to make it easier for developers to quickly create web or mobile apps， without worrying about setting up or managing the underlying infrastructure of servers， storage， network and databases needed for development.

Serverless computing

Overlapping with PaaS， serverless computing focuses on building app functionality without spending time continually managing the servers and infrastructure required to do so. The cloud provider handles the setup， capacity planning and server management for you. Serverless architectures are highly scalable and event-driven， only using resources when a specific function or trigger occurs.

Software as a service （SaaS）

Software as a service is a method for delivering software applications over the Internet， on demand and typically on a subscription basis. With SaaS， cloud providers host and manage the software application and underlying infrastructure and handle any maintenance， like software upgrades and security patching. Users connect to the application over the Internet， usually with a web browser on their phone， tablet or PC.

Uses of cloud computing

The first cloud computing services are barely a decade old， but already a variety of organisations—from tiny startups to global corporations， government agencies to non-profits—are embracing the technology for all sorts of reasons.

Here are a few examples of what is possible today with cloud services from a cloud provider：

Create cloud-native7 applications

Quickly build， deploy and scale applications—web， mobile and API8. Take advantage of cloud-native technologies and approaches， such as containers， Kubernetes9， microservices architecture， API-driven communication and DevOps10.

Test and build applications

Reduce application development cost and time by using cloud infrastructures that can easily be scaled up or down.

Store， back up and recover data

Protect your data more cost-efficiently—and at massive scale—by transferring your data over the Internet to an offsite cloud storage system that is accessible from any location and any device.

Analyse data

Unify your data across teams， divisions and locations in the cloud. Then use cloud services， such as machine learning and artificial intelligence， to uncover insights for more informed decisions.

Stream11 audio and video

Connect with your audience anywhere， anytime， on any device with high-definition video and audio with global distribution.

Embed intelligence

Use intelligent models to help engage customers and provide valuable insights from the data captured.

Deliver software on demand

Also known as software as a service （SaaS）， on-demand software lets you offer the latest software versions and updates around to customers—anytime they need， anywhere they are.

簡單來說，云計算就是通過因特網(wǎng)（“云”）提供計算服務(wù)——包括服務(wù)器、存儲功能、數(shù)據(jù)庫、聯(lián)網(wǎng)、軟件、分析功能和智能功能——以加快創(chuàng)新、使資源配置更靈活，實現(xiàn)規(guī)模經(jīng)濟。通常你只需為自己所使用的云服務(wù)付費，這有助于降低運營成本，更高效地運行基礎(chǔ)設(shè)施，并根據(jù)業(yè)務(wù)需求的變化作出調(diào)整。

云計算的好處

云計算不同于企業(yè)對IT資源的傳統(tǒng)認知，它是一項重大變革。以下是各機構(gòu)選擇云計算服務(wù)的七個常見理由。

成本

云計算免除了用以購買硬件和軟件以及構(gòu)建并運行本地數(shù)據(jù)中心的資本支出，包括服務(wù)器機架、機器運行和冷卻需要的全天候供電，還有維護基礎(chǔ)設(shè)施的IT專業(yè)人員——這些費用增長很快。

速度

大多數(shù)云計算服務(wù)都可自助按需提供，通常只要點幾下鼠標，即便是海量計算資源也能在幾分鐘之內(nèi)配置好，這給了企業(yè)極大的靈活性，也減輕了容量規(guī)劃的壓力。

全球范圍

云計算服務(wù)的其中一個好處就是彈性縮放的能力。用云術(shù)語來講，這意味著在剛好需要的時候，從合適的地理位置交付恰當(dāng)數(shù)量的IT資源，例如，更多或更少的計算能力、存儲空間和帶寬。

生產(chǎn)率

本地數(shù)據(jù)中心通常需要做許多與“機架和堆?！毕嚓P(guān)的工作，包括設(shè)置硬件、給軟件打補丁，以及其他耗時的日常IT管理事務(wù)。云計算省去了對其中很多工作的需求，因此IT團隊可以有時間實現(xiàn)更重要的商業(yè)目標。

性能

最大的云計算服務(wù)都在各安全數(shù)據(jù)中心所組成的全球網(wǎng)絡(luò)上運行，這些數(shù)據(jù)中心定期升級為最新一代快速高效的計算硬件。相比單個企業(yè)數(shù)據(jù)中心，這有幾點好處，包括減少應(yīng)用程序的網(wǎng)絡(luò)延遲和擴大規(guī)模經(jīng)濟效應(yīng)。

可靠性

云計算使得數(shù)據(jù)備份、災(zāi)難恢復(fù)和保持業(yè)務(wù)連續(xù)性更容易，費用更低，因為數(shù)據(jù)可做成鏡像保存在云提供商網(wǎng)絡(luò)的多個冗余站點上。

安全性

很多云提供商提供各種政策、技術(shù)和控制工具，全面加強你的安全態(tài)勢，有助于保護你的數(shù)據(jù)、應(yīng)用程序和基礎(chǔ)設(shè)施免遭潛在威脅。

云計算的種類

云服務(wù)有三種不同的使用方式：公有云、私有云或混合云。

公有云

公有云由第三方云服務(wù)提供商所有和運營，云服務(wù)提供商通過因特網(wǎng)提供他們的計算資源，如服務(wù)器和存儲功能。微軟的Azure就是公有云的一個例子。在公有云中，所有的硬件、軟件和其他支持性基礎(chǔ)設(shè)施均由云提供商所有和管理。你可以用網(wǎng)頁瀏覽器來獲得這些服務(wù)并管理你的賬戶。

私有云

私有云是指專供單個企業(yè)或機構(gòu)使用的云計算資源。私有云可實際位于公司的本地數(shù)據(jù)中心內(nèi)。有些公司也會雇請第三方服務(wù)提供商托管他們的私有云。私有云是在專用網(wǎng)絡(luò)上維護服務(wù)和基礎(chǔ)設(shè)施的云。

混合云

混合云結(jié)合了公有云和私有云的特點，通過共享數(shù)據(jù)和應(yīng)用程序的技術(shù)將兩者連接在一起。通過允許數(shù)據(jù)和應(yīng)用程序在私有云和公有云之間移動，混合云可以為企業(yè)提供更大的靈活性和更多的部署策略，幫助優(yōu)化企業(yè)現(xiàn)存的基礎(chǔ)設(shè)施、安全性和兼容性。

云服務(wù)的類型：基礎(chǔ)設(shè)施即服務(wù)，平臺即服務(wù)，無服務(wù)器，軟件即服務(wù)

大多數(shù)云計算服務(wù)可以分成四大類：基礎(chǔ)設(shè)施即服務(wù)，平臺即服務(wù)，無服務(wù)器和軟件即服務(wù)。這些服務(wù)有時會被稱為云計算堆棧，因為它們是逐層建構(gòu)的。

基礎(chǔ)設(shè)施即服務(wù)

這是云計算服務(wù)中最基礎(chǔ)的類型。使用基礎(chǔ)設(shè)施即服務(wù)時，你以即用即付的方式從云提供商處租用IT基礎(chǔ)設(shè)施，包括服務(wù)器和虛擬機、存儲空間、網(wǎng)絡(luò)、操作系統(tǒng)。

平臺即服務(wù)

平臺即服務(wù)指的是按需提供環(huán)境用于開發(fā)、測試、交付和管理軟件應(yīng)用的云計算服務(wù)。平臺即服務(wù)旨在讓開發(fā)者更輕松地快速構(gòu)建網(wǎng)頁端或移動端應(yīng)用程序，而無須操心設(shè)置或管理開發(fā)所需的服務(wù)器、存儲功能、網(wǎng)絡(luò)和數(shù)據(jù)庫等基礎(chǔ)設(shè)施。

無服務(wù)器計算

無服務(wù)器計算與平臺即服務(wù)有所重合，專注于構(gòu)建應(yīng)用程序的功能，無須在持續(xù)管理必要的服務(wù)器和基礎(chǔ)設(shè)施上花費時間。云提供商為你處理設(shè)置、容量規(guī)劃和服務(wù)器管理事宜。無服務(wù)器架構(gòu)可伸縮性強，而且由事件驅(qū)動，只有在特定函數(shù)或觸發(fā)器發(fā)生時才會使用資源。

軟件即服務(wù)

軟件即服務(wù)是指通常以訂閱方式經(jīng)由因特網(wǎng)按需交付軟件應(yīng)用程序的方式。使用軟件即服務(wù)時，云提供商托管軟件應(yīng)用程序和基礎(chǔ)設(shè)施并負責(zé)所有維護工作，如升級軟件、打安全補丁。用戶通常用手機、平板電腦或個人電腦上的網(wǎng)頁瀏覽器通過因特網(wǎng)連接到應(yīng)用程序。

云計算的用途

距第一批云計算服務(wù)問世還不到十年，但已有各種機構(gòu)——從小型初創(chuàng)企業(yè)到跨國公司，從政府機構(gòu)到非盈利機構(gòu)——因各種原因采用云計算技術(shù)。

以下是目前云提供商所能提供的云服務(wù)的一些實例：

構(gòu)建云原生應(yīng)用程序

快速構(gòu)建、部署和縮放應(yīng)用程序，包括網(wǎng)頁端、移動端和應(yīng)用程序編程接口。利用云原生技術(shù)和方法，比如容器、Kubernetes、微服務(wù)架構(gòu)、API驅(qū)動的通信和DevOps。

測試和構(gòu)建應(yīng)用程序

通過使用可輕松升降級的云基礎(chǔ)設(shè)施來縮減應(yīng)用程序的開發(fā)成本和時間。

存儲、備份和數(shù)據(jù)恢復(fù)

通過將數(shù)據(jù)由因特網(wǎng)傳送到從任何位置、任何設(shè)備都可訪問的場外云存儲系統(tǒng)中，以超大規(guī)模和更具成本效益的方式保護數(shù)據(jù)。

分析數(shù)據(jù)

統(tǒng)一云中各團隊、各部門、各地區(qū)的數(shù)據(jù)。然后用云服務(wù)（例如機器學(xué)習(xí)和人工智能）發(fā)掘洞見以做出更有根據(jù)的決定。

在線播放音頻和視頻

用遍布全球的高清視頻和音頻在任何地點、任何時間、任何設(shè)備上與受眾進行聯(lián)系。

內(nèi)嵌智能

用智能模式來吸引客戶，利用捕獲的數(shù)據(jù)提供有價值的見解。

按需提供軟件

按需軟件也被稱為軟件即服務(wù)，可以讓你向客戶提供最新的軟件版本和更新——無論他們身在何處，何時需要。

（譯者為“《英語世界》杯”翻譯大賽獲獎?wù)撸?/p>