Typically, a web hosting service gives you the option of selecting either a traditional hard drive or a solid-state drive as your website's storage medium. Traditional hard drives have large capacities and lower prices, but they aren't quite as resilient as their SSD counterparts. Solid-state drives, on the other hand, are often faster and more reliable than HDDs, but they cost more and have smaller storage capacities. Unless you truly need blazing speed, a traditional hard drive should get the job done.
The force driving server virtualization is similar to that which led to the development of time-sharing and multiprogramming in the past. Although the resources are still shared, as under the time-sharing model, virtualization provides a higher level of security, dependent on the type of virtualization used, as the individual virtual servers are mostly isolated from each other and may run their own full-fledged operating system which can be independently rebooted as a virtual instance.