All devices on the World Wide Web are recognized by a special number called an IP address, for example 220.127.116.11. In case you have a site, the domain name that you enter to access it is for your convenience, but the server where your site files are still has an IP address. As there are far more sites and devices than there're IPs, all the shared hosting servers have a number of sites under an identical IP, while with a dedicated server you'll be given a dedicated IP as well. Even in the first case though, you're able to obtain a dedicated IP for your sites and host them on a shared server. One benefit would be that you'll enjoy superior search engine positions as a dedicated IP usually means a quicker loading site. In addition, you need such an IP when you intend to acquire an SSL certificate for your site and shield the data that visitors submit on it.