In regards to hosting, cloud architecture refers to using a different server for each and every part of the Internet hosting service. Such a setup leads to better performance as one machine will be used just for file storage, a different one only for running databases, and so on, therefore different system processes will not run on the very same machine. This will lessen the probability of system errors significantly and will allow your websites to run faster, not mentioning the higher uptime. In case you are looking for such a service, you need to double check that you'll really find it as lots of companies advertise cloud web hosting packages, but the control panels they use aren't designed to function in a true cloud and can function only on one server. The trouble with using just a single machine is that if one service goes down or generates high load, the entire server will possibly go offline, so your sites will no longer be accessible.