All devices on the Internet are identified by a special number called an IP address, for instance 123.123.123.123. In case you have a website, the domain name that you type in order to open it is to save you time, however the server where the website files are still has an IP. Since there're a lot more sites and devices than there are IP addresses, all of the shared hosting servers have a number of sites under the very same IP, while using a dedicated server you'll have a dedicated IP as well. Even in the first case though, you will be able to obtain a dedicated IP for your websites and host them on a shared server. One benefit would be that you'll get far better search engine rankings because a dedicated IP often means a quicker loading site. What's more, you need such an IP if you plan to acquire an SSL certificate for your website and protect the information that your visitors submit on it.