When it comes to web hosting, cloud architecture refers to using an independent server for every single aspect of the Internet hosting service. Such a setup leads to improved performance since one machine will be used just for file storage, another one only for running databases, etcetera, thus different system processes will not run on the same machine. The latter will minimize the probability of system errors considerably and will allow your sites to operate faster, not mentioning the better uptime. If you're looking for this type of service, it is important to double check that you'll really receive it as many companies advertise cloud internet 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 issue with using a single machine is that in case one service crashes or generates high load, the entire server will almost certainly go offline, so your Internet sites will no longer be accessible.