In regards to web hosting, cloud architecture refers to using a separate server for every single part of the Internet hosting service. Such a setup leads to a lot better performance since one machine will be used just for file storage, a different one just for running databases, and so on, so different system processes will not run on the very same machine. This will minimize the chance of system errors substantially and will allow your websites to operate faster, not mentioning the better uptime. When you're looking for this type of service, you need to double check that you'll really find it as lots of companies advertise cloud hosting plans, however the control panels they use are not designed to work in a genuine cloud and can operate only on a single server. The trouble with using just a single machine is that if one service crashes or generates high load, the whole server will most probably go offline, so your websites will no longer be accessible.