I was talking to a client recently and he was asking me “What is this Cloud Computing all about?”. So I was explaining that, instead of maintaining your own servers at your own offices, you use servers and applications that run on systems which are in remote data centres. That means that, while you do need to administer the cloud based applications, you don’t have to buy expensive servers and pay for hardware maintenance. Instead the costs are spread evenly and you can scale the cloud based apps as your requirements grow or shrink.
He then said to me, “So Cloud Computing is like electricity then! While you could buy your own generator and produce electricity for the factory, it’s much more cost effective to buy your electricity from a provider. Then you only pay for what you use and you don’t have to buy and maintain expensive generator’s as your needs change.”
That is by far the best explanation Cloud Computing I have heard.