All devices on the Web are identified by a unique number called an IP address, for instance 220.127.116.11. In case you have a website, the domain name that you type to be able to access it is to save you time, but the server where your website files are still has an IP address. Due to the fact that there are many more sites and devices than there are IPs, all of the shared website hosting servers have a number of sites under the same IP, whereas when you use a dedicated server you will have a dedicated IP as well. Even in the first case though, you can obtain a dedicated IP for your websites and host them on a shared server. An advantage would be that you may get superior search engine rankings since a dedicated IP generally means a quicker loading website. What is more, you need such an IP when you want to buy an SSL certificate for your website and shield the information that your visitors submit on it.