All devices on the Web are recognized by a unique number called an IP address, for instance 188.8.131.52. If you have a site, the domain name that you type to load it is for your convenience, yet the server where the website files are still has an IP address. Due to the fact that there're many more websites and devices than there are IPs, all the shared web hosting servers have a number of sites under the same IP, while using a dedicated server you'll have a dedicated IP as well. Even in the first case though, you are able to acquire a dedicated IP for your websites and host them on a shared server. An advantage would be that you may enjoy better search engine rankings as a dedicated IP usually means a faster loading site. What is more, you need such an IP when you intend to acquire an SSL certificate for your site and secure the data that visitors submit on it.