What is "cloud computing "?

I just read an article about cloud computing from www.51cto.com.ArticleIt is interpreted:

Cloud computing is the development of distributed processing (Distributed Computing), parallel processing (Parallel Computing), and grid computing, or the commercial implementation of these computer science concepts.

However, I think the above explanation of "cloud computing" is different from what I understand. I personally think: cloud computing is a later version of SOA thinking. SOA functions software B2B, which may be just a small scope. Cloud computing provides software services, resources, and computing capabilities across the world, so that people who need a specific resource or function do not need to develop or develop them by themselves, directly from the cloud. Like the Internet, global information sharing is achieved. Cloud computing is more extensive and

Function and resource sharing.