All devices on the World Wide Web are identified by a specific number called an IP address, for instance 184.108.40.206. When you have a website, the domain name that you type to load it is for your convenience, yet the server where your website files are still has an IP. Since there are far more websites and devices than there're IPs, all of the shared website hosting servers have a number of websites under the very same IP, whereas when you use a dedicated server you will have a dedicated IP too. Even in the first case though, you will be able to get a dedicated IP for your websites and host them on a shared server. An advantage would be that you will enjoy better search engine rankings because a dedicated IP generally means a quicker loading site. What is more, you need such an IP in case you intend to acquire an SSL certificate for your site and shield the information that visitors submit on it.