These servers contain high capacity hard disks. It allows to run more complicated applications such as databases, video and audio, etc. User can maintain more than one websites on this dedicated server.
Dedicated server is required for websites which have large number of visits. Such websites need more bandwidth. Shared servers not provide such a full range of bandwidth. Using a dedicated server is more beneficial because of you do not need to bother about hardware or operating systems and you will be free from extra expensive. In a dedicated server software support is unlimited.
Normally a dedicated server is about $150 to $750 per month.