In regards to Internet hosting, cloud architecture refers to using a separate server for each aspect of the hosting service. Such a setup leads to a lot better performance because one machine will be used just for file storage, another one only for running databases, and so on, thus different system processes will not run on the exact same machine. This will reduce the chance of system errors significantly and will allow your Internet sites to run faster, not mentioning the greater uptime. When you are looking for this kind of service, it is important to double check that you will really receive it as lots of companies advertise cloud hosting packages, but the control panels they use aren't designed to function in a true cloud and can work only on one server. The problem with using just a single machine is that in case one service fails or generates high load, the whole server will most probably go offline, so your websites will no longer be accessible.