All devices on the Web are identified by a special number called an IP address, such as 126.96.36.199. If you have a website, the domain that you enter to be able to access it is to save you time, however the server where your site files are still has an IP. Since there're far more websites and devices than there are IP addresses, all the shared hosting servers have a number of sites under the same IP, while when you use a dedicated server you'll have a dedicated IP too. Even in the first case though, you will be able to get a dedicated IP for your sites and host them on a shared server. One benefit would be that you will have improved search engine rankings because a dedicated IP usually means a quicker loading website. In addition, you need such an IP if you plan to purchase an SSL certificate for your website and protect the information that your visitors submit on it.