1.国际会计准则：
基础设施即服务 (IAAS) 是将计算基础设施作为按需服务交付的方式。它是三种基本的云服务模型服务器存储网络操作系统之一。在用户购买服务器软件数据中心空间或网络设备并租用这些资源作为完全外包服务可以需求模型。它允许动态扩展并且资源作为服务分发。通常包括单个硬件上的多个用户。
2. PAAS :
平台即服务 (PAAS) 是由第三方管理的服务组成的应用程序的云交付模型。它为您的应用程序提供弹性扩展，允许开发人员通过互联网构建应用程序和服务，部署包括公共、私有和混合。
3. SAAS：
软件即服务 (SAAS) 允许用户运行现有的在线应用程序，它是一种模型软件，它部署为托管服务并通过输出改写/重写文本访问互联网或软件交付模型，在此期间软件及其相关数据集中托管并使用他们的客户端访问，通常是网络上的在线浏览器。 SAAS 服务用于现代应用程序的开发和部署。
IAAS、PAAS和SAAS的区别：
| Basis Of | IAAS | PAAS | SAAS |
|---|---|---|---|
| Stands for | Infrastructure as a services. | Platform as a services. | Software as a services. |
| Uses | IAAS is used by network architects. | PAAS is used by developer. | SAAS is used by end user. |
| Access | IAAS give access to the resources like virtual machines and virtual storage. | PAAS give access to run time environment to deployment and development tools for application. | SAAS give access to the end user. |
| Model | It is service model that provide visualized computing resources over internet. | It is a cloud computing model that delivers tools that is used for development of application. | It is a service model in cloud computing that host software make available for client. |
| Technical understanding. | It required technical knowledge. | In which you required knowledge of subject to understand basic setup. | There is no requirement about technicalities company handle everything. |
| Popularity. | It is popular between developer and researchers. | It popular between developer who focus on the development of apps and scripts. | It is popular between consumer and company.such as file sharing, email and networking. |
| Cloud services. | Amazon web services, sun, vcloud express. | Facebook, and google search engine. | M.S office web, Facebook and google apps. |
| Enterprise services. | AWS virtual private cloud. | Microsoft azure. | IBM cloud analysis. |
| Outsourced cloud services. | Salesforced. | Force.com, Gigaspaces. | AWS, terremark |