Sadly, “The Cloud” is a term much abused these days; much like the word “Hoover” which apparently, in the UK at least, applies to any vacuum cleaner whether or not it is actually a Hoover. Everyone and anyone seems to label their service with the term Cloud so long as it appears like it might actually be the cloud. So what actually is the cloud?
In history, the cloud is that thing that appears on an infrastructure diagram, the icon the represents the Internet and all that goes with it. Like a 21st Century equivalent of the remark “ere be dragons”, the cloud picture represents something that is too hard to draw – even if you wanted to try – but it is something that is an essential part of our infrastructure. I’ve drawn thousands of web architectures with the cloud on the right (or left, depending on the day) and it was there to deliver our visitors to our site; without it out efforts would have been worthless.
So the Cloud is the Internet and any service labeled as being “Cloud” is not the Cloud unless it is actually in the Cloud. Alot of hosting providers label their services as Cloud because that is what the market demands, not because they actually are in the Cloud. They offer a service on the other side of the Cloud. Like East and West Berlin with the Cloud being the gap between the two, hosting providers are no more the Cloud than your own Infrastructure. That is not to say they can’t offer virtualization, per minute billing and elasticity (many don’t) but it is more to say they have a protected network or data center that they maintain. Amazon, which is in the cloud, provides you with a service that is somewhere. You will be unable to draw it on a diagram because you have simply no idea where it is or even what it looks like.