Virtual dedicated servers represent an option for hosting services which leverage more control into the hands of the website owner, such as root access, the availability to install your own software on the servers, your own dedicated IP.  Much like shared hosting services, most of these options can come in a la cart fashion, letting you choose the amount of bandwidth usage, storage, and options you need.  It offers more personal control over your server, but you still share a single enterprise level computer with several (instead of hundreds, like in shared hosts) other website customers.  The single computer has its hard drive partitioned, and each customer gets their own partition of the computer.  This varies from dedicated servers, where a single person rents the entire computer.