All devices on the Web are identified by a specific number called an IP address, for example 220.127.116.11. In case you have a site, the domain name that you type to open it is for your convenience, yet the server where the site files are still has an IP. As there are a lot more sites and devices than there're IP addresses, all the shared web hosting servers have a number of sites under an identical IP, whereas with a dedicated server you will have a dedicated IP too. Even in the first case though, you are able to obtain a dedicated IP for your websites and host them on a shared server. One advantage would be that you may enjoy better search engine rankings since a dedicated IP usually means a faster loading website. Furthermore, you need such an IP when you plan to get an SSL certificate for your website and shield the information that visitors submit on it.