When you host a site on a server, it uses the server's shared IP address - a unique number that's used to detect every device connected to the Web. The domain name which you use for the website is for easy accessibility and convenience of the website visitors, but on a lower level, their web browser connects to the IP address of the server. As there're a lot more websites than IPs, shared hosting servers use a single IP for a number of sites even in case they belong to several users. While this doesn't affect your website performance directly, having a dedicated IP may slightly boost the loading speed of a particular website, giving it higher rankings in search engine results. Such an IP is required for the installation of an SSL certificate too, so if you plan to protect the payment or login data that your site visitors submit, you need an IP alongside the SSL.
