An IP address is a unique number that distinguishes a site or a hosting server on the world-wide web, so if you have a dedicated IP, it shall be employed only by your Internet sites and shall not be shared with other individuals as it happens with shared hosting accounts. In case you have your own server, you shall have a dedicated IP, but you may require extra ones for a variety of purposes. If you have an electronic store, for example, you'll need an SSL certificate for it, in order to ensure that the payment info which your clients submit shall be encrypted and protected. The same is valid if you have a login form of some sort and you would like the usernames and the passwords that visitors input to be protected. The SSL certificate requires a dedicated IP, which ought to be different from the one which you already have on the server. You may also need an individual IP for an application such as a VoIP server, or if you would like a slightly better performance for a particular Internet site, which will influence its position in search engine results.