Dedicated server hosting and a dedicated shared hosting is two different things. When a person is using dedicated server hosting they are using a server that only hosts their website. When a person is using a dedicated shared host they are actually sharing the site with others. When using the shared server they must use only an allocated amount of space and bandwidth.
The costs of these services will vary depending on which you use. Shared servers will pay less for the website since they share the costs with the other site owners. While, a dedicated server will cost more since there is no one to share the cost with.
