If you host a website on a server, it employs the server's shared IP - a unique number that's used to detect any device connected to the Net. The domain name which you use for the website is for easy accessibility and convenience of the website visitors, but on a more basic level, their browser connects to the IP address of the server. Because there are far more websites than IP addresses, shared web hosting servers use the very same IP for many different sites even if they belong to different users. While this does not affect your site performance directly, having a dedicated IP may slightly increase the loading speed of a certain website, giving it better positions in search engine results. Such an IP is needed for the installation of an SSL certificate too, so if you wish to protect the payment or login info that your site visitors enter, you should have an IP alongside the SSL.