All devices on the Web are identified by a unique number called an IP address, such as 123.123.123.123. If you have a website, the domain name that you type in order to open it is to save you time, but the server where the website files are still has an IP. Because there are many more websites and devices than there are IP addresses, all shared website hosting servers have a number of sites under the very same IP, while using a dedicated server you'll get a dedicated IP too. Even in the first case though, you will be able to get a dedicated IP for your websites and host them on a shared server. One benefit would be that you'll get improved search engine rankings since a dedicated IP usually means a faster loading site. What's more, you need such an IP in case you intend to buy an SSL certificate for your website and shield the data that visitors submit on it.