Skip to Main Content
As a kind of emerging business computational model, Cloud Computing distribute computation task on the resource pool which consists of massive computers, accordingly ,the application systems can gain the computation strength, the storage space and software service according to its demand. Cloud computing can be viewed from two different aspects. One is about the cloud infrastructure which is the building block for the up layer cloud application. The other is of course the cloud application. By means of three technical methods, cloud computing has achieved two important goals for the distributed computing: high scalability and high availability. Scalability means that the cloud infrastructure can be expanded to very large scale even to thousands of nodes. Availability means that the services are available even when quite a number of nodes fail. This paper discusses the evolution process of cloud computing, the current technologies adopted in cloud computing, as well as the systems in enterprises. This paper introduced with emphasis the Amazon Elastic Compute Cloud, the cloud computing platform of Google and "blue cloud" of IBM, analyze and compare three kinds of cloud computing platform.