Cloud Computing

The term "cloud" in cloud computing means "Internet" and the computing part is the use of computer technology. Cloud computing is a huge infrastructure or system that delivers "hosted services over the internet." Cloud computing has three significant characteristics to it that make it different from any regular hosting service.
"1) It is sold on demand (by the hour or the minute), 2) the user can have as much or as little service as they want and 3) all the user needs is a computer and Internet access." http://searchcloudcomputing.techtarget.com/sDefinition/0,,sid201_gci1287881,00.html

All of this "cloud computing" seems very confusing to me and I do not quite understand it. I think that it being such a huge network, I can't quite wrap my head around what it is used for and how it is used. If one knew what they were doing and knew exactly what they needed from these services, it would be a very easy option.

cube tree (using something called "social documents"), doc verse (foucused on sharing documents), and social calc (a spreadsheet leader) all look easy to use (again, if you understand what youre doing,) but social calc, in my opinion, looks like it would be the easiest to use or the most practical. It seems more organized and would be more efficient.

Again, maybe because I have never used anything like this before, the fact that it's such a large system, or maybe because it's hard for anyone to explain it the same way... Cloud computing is not something that I understand.