All devices on the Internet are identified by a unique number called an IP address, such as 18.104.22.168. If you have a site, the domain that you type to be able to open it is to save you time, but the server where your website files are still has an IP. Considering that there are a lot more sites and devices than there are IPs, all shared web hosting servers have a number of websites under an identical IP, whereas using a dedicated server you'll be given 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 benefit would be that you may get superior search engine rankings as a dedicated IP usually means a faster loading site. What's more, you need such an IP in case you plan to buy an SSL certificate for your website and secure the data that visitors submit on it.