All devices on the Web are recognized by a special number called an IP address, for instance 18.104.22.168. When you have a website, the domain that you enter to access it is to save you time, but the server where your site files are still has an IP. Because there're far more sites and devices than there are IP addresses, all shared website hosting servers have a number of sites under an identical IP, while using a dedicated server you'll be given a dedicated IP as well. Even in the first case though, you can acquire a dedicated IP for your sites and host them on a shared server. One benefit would be that you will enjoy superior search engine positions because a dedicated IP usually means a quicker loading website. What is more, you need such an IP in case you would like to obtain an SSL certificate for your site and shield the info that visitors submit on it.