With VPS Hosting, you have complete isolation. This means that no matter what other users might be doing on the server, your VPS package will be unaffected. With root access, you can install whatever applications you require.
VPS also gives you guaranteed resources, so no matter what, the CPU, RAM, Disk Space and Bandwidth allocated to your VPS Hosting package will always be available for your applications. It gives you all the features and functions of a Dedicated server, without the additional cost.