What exactly is cloud computing? What's the use?

Because when we represent the Internet, we usually draw a cloud. Generally speaking, a cloud is a large number of computers connected through a network.

Cloud computing is to connect a large number of ordinary low-cost computers through the network and become a "supercomputer" through software to provide computing and processing services to the outside world. Instead of the traditional expensive mainframe and minicomputer applications, higher performance is obtained and the cost is greatly reduced.

For example, if the price of a traditional server is 100W, then in the cloud mode, 25W can be a perfect substitute in the form of cheap PC cluster: it can provide the same high reliability guarantee, and it can also provide more storage capacity and faster processing power than the traditional server 100W, and develop more applications that are difficult to realize on the traditional server based on these, which is the benefit of cloud computing.