All devices on the Web are recognized by a special number called an IP address, such as 220.127.116.11. When you have a site, the domain name that you enter in order to load it is for your convenience, but the server where your site files are still has an IP address. Since there are far more websites and devices than there're IP addresses, all the shared website hosting servers have a number of sites under the same IP, while using 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 benefit would be that you will have better search engine rankings since a dedicated IP often means a quicker loading site. In addition, you need such an IP if you want to buy an SSL certificate for your site and shield the information that your visitors submit on it.