What's the difference between cloud computing and hosting on a online web server?

Could somebody please explain to me what cloud computing is in laymen's terms?What's the difference between cloud computing and hosting on a online web server?
To put it simple, Dedicated servers have limited resources. There is a limit on the number of processors or hard drives that you can put into a dedicated server. You cannot run 100k websites from one dedicated server.



But you can do that with a cloud hosting, as you can add the same server hardware to a cloud, and the power of the cloud will just go on increasing. The resources of all the servers and computers in the cloud are shared, and therefore, a reseller hosting company can virtually host billions and billions of sites in what would look like just 1 server, but which actually is a cloud of several hundreds of servers.



Cloud hosting in a very large scale is highly profitable since management costs would come down, however, the hardware costs would just remain the same.What's the difference between cloud computing and hosting on a online web server?
First, the easy one... hosting on a web server is when you upload files to a server so they can be downloaded again by you, or by other people you give permission to.



With cloud computing, you're using applications (like email, word processing, spreadsheet, photo editing) that are located on a remote server somewhere, but using them as if they were programs on your computer. Google Apps (Google Documents, etc.) would be a good example of that. The program lives on a remote server, but you're using it on your computer inside a web browser, and usually saving your files to the remote server so they can be accessed from any computer you use.



So part of cloud computing involves uploading files to a web server, but it has more to do with the fact that you're using a program that lives on that server to help you create the files to begin with.



Does that clear things up?What's the difference between cloud computing and hosting on a online web server?
In practical terms, there is no difference. Cloud computing is just a buzzword that means a lot of different things depending on what company is selling something. In general terms the term "cloud" means "don't worry about how, it just happens and it just works".



Cloud computing, to me, is simply the provision of technology-based resources (processor power, storage, networking) on demand, just like the power company provides you with electricity to the plugs in your house.



If you want to read a bit more about it check out the Wikipedia entry at http://en.wikipedia.org/wiki/Cloud_compu鈥?/a>



For an example of a currently available, real-world and seemingly successful cloud computing service, check out the Amazon Simple Storage Service (S3) at http://aws.amazon.com/s3/ . Other examples include Yahoo! Mail, Hotmail, and the Google search engine. They all run "in the cloud". They don't run on YOUR PC, right? ;-)



If you REALLY want to read more about it go to the library and get a copy of "The Big Switch" by Nicholas Carr. I'm just starting to read it and it's very interesting, not "techie" boring stuff, but "big-picture, history-making-and-changing innovation" kind of stuff.