
24 Chaowei Yang and Qunying Huang
management, and domain applications. If the cloud provider supplies the
cloud service as a virtual computing server including the three lower layers,
the service mode is called IaaS, such as Amazon EC2. If the cloud provider
supplies the cloud service as a platform comprising the lower four layers for
developing, testing, and deploying applications and software, the service
mode is called PaaS, such as Windows Azure with Visual Studio. If the
cloud provider supplies the cloud service as software including the lower ve
layers, the service mode is called SaaS, such as Gmail and Google Earth. If
the cloud pro ...