Quantity of services. Because actually all our hosting services offer the same performance, but targeted to different types of users. So the question here is what you want to do. And then, once you know it, we can add as much resources as required (more disk, more band with, more emails) but for your concrete project.

Another related difference is price. Because more services require more Hardware. So, if for whatever reason you are using a hosting that is not adjusted to your needs you will end up paying more for less needs, with the same quality in all cases.