All devices on the World Wide Web are identified by a unique number called an IP address, for example 126.96.36.199. When you have a site, the domain name that you enter to open it is to save you time, yet the server where the site files are still has an IP address. Since there are many more sites and devices than there are IPs, all the shared website hosting servers have a number of sites under an identical IP, while with a dedicated server you'll get a dedicated IP too. Even in the first case though, you're able to acquire a dedicated IP for your websites and host them on a shared server. One advantage would be that you'll get far better search engine rankings as a dedicated IP usually means a quicker loading site. In addition, you need such an IP if you intend to purchase an SSL certificate for your website and shield the info that visitors submit on it.