An IP address is a unique number that identifies a website or a web server on the world-wide web, so in the event that you have a dedicated IP, it'll be used solely by your Internet sites and will not be shared with other individuals as it happens with shared hosting accounts. If you have your own server, you shall have a dedicated IP, but you may require extra ones for various purposes. In case you have an electronic store, for instance, you shall need an SSL certificate for it, so as to ensure that the payment information your customers submit will be encrypted and safe. The same is valid in case you have a login form of some type and you would like the usernames and the passwords which visitors enter to be secured. The SSL certificate requires a dedicated IP, which needs to be different from the one which you already have on the server. You may also need an independent IP for an application such as a VoIP server, or if you would like a slightly better performance for a particular site, which will influence its position in search engine results.