Cloud computing tiering:Infrastructure (infrastructure)-as-a-service,platform (platform)-as-a-service,software (software)-as-a-service. Infrastructure at the bottom, platform in the middle, software at the top. Other "soft" layers can be added on top of these layers.
Iaas:infrastructure-as-a-service (infrastructure as a service)The first layer is called IaaS, sometimes called Hardware-as-a-service, and a few years ago if you want to run some business applications in your office or on your company's website, you need to buy servers or other high-level hardware to control your local applications and get your business up and running.
But with IaaS now, you can outsource your hardware to other places. IaaS will provide off-site servers, storage and network hardware that you can rent. Save on maintenance costs and office space, companies can use these hardware at any time to run their applications.
Some large IaaS companies include Amazon, Microsoft, VMWare, Rackspace and Red Hat. However, these companies have their own expertise, such as Amazon and Microsoft provide you with not only IaaS, they will also rent their computing power to you to host your site.
Paas:platform-as-a-service (Platform as a service)The second layer is called PAAs, which is sometimes called middleware. All the development of your company can be done at this level, saving time and resources.
PAAs offers a variety of solutions for developing and distributing applications on the web, such as virtual servers and operating systems. This saves you money on the hardware and makes it easier to collaborate between decentralized studios. Web application management, application design, application virtual hosting, storage, security and application development collaboration tools, etc.
Some large PAAs providers have Google App engine,microsoft azure,force.com,heroku,engine Yard. Recent companies have Appfog, Mendix and standing Cloud
Saas:software-as-a-service (software as a service)The third layer is called SaaS. This layer is a layer of daily contact with your life, most of which is accessed through a Web browser. Any application on a remote server can be run over the network, which is SaaS. It is a mode of providing software through the Internet, the manufacturer unifies the application software on its own server, the customer can order the required application software service through the Internet to the manufacturer according to their actual demand, and pay the vendor according to the amount and time of the service ordered. And through the Internet to obtain the services provided by the manufacturer. Users do not need to purchase software, but instead of renting web-based software to the provider to manage business activities, without the need for software maintenance, the service provider has full control and maintenance software, software vendors to provide customers with Internet applications, but also provide software offline operation and local data storage, Allows users to use their ordered software and services anytime, anywhere. For many small businesses, SaaS is the best way to adopt advanced technologies that eliminate the need for businesses to purchase, build, and maintain infrastructure and applications.
The services you consume are completely accessible from websites such as Netflix, MOG, Google Apps, Box.net, Dropbox or Apple's icloud. Although these Web services are used for business and entertainment or both, this is part of cloud technology.
Some of the SaaS applications used for business include Crm,adp,workday and SuccessFactors of Citrix's Gotomeeting,cisco Webex,salesforce.
From for notes (Wiz)
Iaas,paas,saas
