Cloud Server "flexibility" is reflected in what areas?

We all know that cloud computing has expanded elastic properties, called elasticity that cloud of available resources with the needs of users and can be flexible and change, free lift, during peak or trough, can match the right amount of resources, neither stretched not too much waste. Elastic cloud server, simply put, is a virtual server running on a cloud computing environment, computing resource scheduling allows users to freely, without the limitations of traditional hardware.
Elastic cloud server has good scalability, enabling users online at any time of the memory, disk and bandwidth server system for flexible adjustment; With the cost advantage of cluster deployment, greatly reducing IT deployment and business operation and maintenance costs; due to the fragmentation of services in multiple hosts, and even more room, it is not easy to completely downtime, strong resilience fault tolerance, to ensure long-line, make your site more secure and reliable.
In general, the cloud server "elastic", mainly reflected in several aspects of elastic resources calls, billing elastic, and resilient business management and so on.
Elastic resource called here "elastic" is relatively traditional in terms of servers, traditional IT environments, the user is difficult to do configuration changes on a single server. Typically, server purchases will remain intact, at 3--5-year depreciation period, the basic configuration of the server will not change. But after the customer purchases the cloud server, you can adjust the amount of the increase or decrease in business, change server configuration, which is the traditional IDC can not be realized.
Elasticity of billing for small and medium enterprises, mostly facing lack of technical personnel, limited operating costs and other issues, if it continues to buy / lease a large number of server resources, both operation and maintenance can not keep up cause it makes more idle resources; and buy cloud server, only need to use their own resources (networks, servers, storage, applications, services, etc.) paid to improve the efficiency of resource use while also avoiding unnecessary waste, optimized operating costs.
Resilient business management is to calmly deal with traffic "peaks" and "valleys", the cloud server must have a temporary workaround, free expansion capabilities. For example, two-eleven, New Year's big promotion, during the anniversary, often soaring user access will appear, but in the usual server configuration complete enough, do not want to buy more waste, you can upgrade the server temporarily by day, expansion of CPU, memory or network bandwidth up to get through peak-access periods.