cloud 云计算学习

定义


colud computing is  a model for enabling convenient,
ondemand network access to a  shared pool of configurable
computing resources(e.g.,networks,servers,storage,applications,and 
services)that can be rapidly provisioned  and released with minimal 
management effort ofservice provider interzction.


三种服务模式
saas  software as a service
paas  platform as a service
laas ingrastructure as a service


五个特征：
broad network access
rapid elasticity
measured service
on-demand self-service
resource pooling


四种布署模式
public 
private
hybrid
community