SaaS is Software-as-a-service (SaaS) for short, which is a software providing Internet mode, generally defined as "software deployment is hosted by Internet Access", with respect to the traditional software model, SaaS users no longer need to purchase software, and hire a Web-based software to SaaS service provider. SaaS provider for enterprises to build all the infrastructure and network software, hardware, operating platform of information required, and is responsible for all the early implementation, post-maintenance and other services, enterprises need to purchase hardware and software, building a room, recruitment of IT staff, you can use the information system via the Internet. Like turning the tap water can be the same, according to the actual needs of enterprises, leasing software from SaaS provider services.
Price SaaS application software is usually "all-inclusive" fee, to include the usual application software license fees, software maintenance fees and technical support costs, its unity for each user monthly rental fee. saas For the majority of small and medium enterprises, SaaS is the best way to advance the implementation of information technology adoption. But SaaS not only for small and medium enterprises, businesses of all sizes can benefit from SaaS in.
PaaS: Platform-as-a-Service (Platform as a Service)
The second layer is called PaaS, sometimes also known as middleware. You all development can be carried out at this level, saving time and resources.
PaaS company offers a variety of online solutions for developing and distributing applications, such as virtual servers and operating systems. This saves you the cost of the hardware, but also to cooperation between the dispersed studio easier. Web application management, application design, application hosting, storage, security, collaboration and application development tools.
Some large PaaS providers have Google App Engine , in the Microsoft Azure, the Force.com, Heroku, Engine Yard . The recent rise of the company AppFog , Mendix and Standing Cloud
IaaS: Infrastructure-as-a-Service (Infrastructure as a Service)
The first layer is called IaaS, sometimes called Hardware-as-a-Service, a few years ago if you wanted to run some business applications in the office or on the company's Web site, you need to buy a server, or other expensive hardware to control local application, to make your business up and running.
But now there's IaaS, you can outsource the hardware to go anywhere else. IaaS company will provide off-site servers, storage and networking hardware, you can rent. Saves maintenance costs and office space, the company can take advantage of these hardware at any time to run their applications.
IaaS some large companies, including Amazon, Microsoft, VMWare, Rackspace and Red Hat. But these companies in turn have their own expertise, not only IaaS such as Amazon and Microsoft to provide you with, they will be rented to you to computing power host your site.
The Daas is two years, with the development of large segments of the data generated by the current domestic large enterprise-class data services is still at an early stage of development, how effective and legitimate use of colleges and universities to bring big data, accurate information It will be Daas practitioners question on the exam. Is divergent data imputation and data distribution.
In today's cloud computing environment which, IaaS is very mainstream, both Linode or Amazon EC2 or Joyent, have a place, but with the introduction of Google's App Engine, Salesforce's Force.com or PaaS such as Microsoft's Windows Azure Platform so that PaaS began to emerge. On the future of both, especially the competitive relationship between the two, I think, in the short term, because IaaS model advantages in support of the application and the learning curve in these two areas, in the short term it will make IaaS will become the first choice in the developer, but in the long run, because of the high rate of integration PaaS model enables brought economic challenges can be resolved if the PaaS such as versatility and support the application, it will be the development of alternative IaaS those "new favorite."