From HostThyself

A dedicated server is a standalone server that is dedicated to a single user.

Typically you rent a server from the web hosting provider and the server is placed at the web hosting provider's datacentre. Software installation may be provided if the service is managed.

Website owner has full control over the server as they don't share it with other websites (compare with shared or virtual hosting).

Ownership of server machine still belongs to the web hosting provider. Some hosting company have plan that transfer the ownership after a 1 to 2 year contract.