Dedicated Hosting is when the host of the client’s site provides all the equipment needed to host the site. They take responsibility for all the equipment and dedicate a whole server to the client’s websites.
Due to the fact the client has a whole server to their site it means they have control over that server and can choose how to optimise it to benefit them.
This can help websites with lots of websites get their sites hosted cheaper. This is because they have a server so can have multiple sites on that one server.