An IP address is a unique number that separates an Internet site or a hosting server on the world-wide web, so if you have a dedicated IP, it will be used solely by your Internet sites and shall not be shared with other individuals as it happens with shared hosting accounts. Provided you have your own server, you will have a dedicated IP, but you may need extra ones for various purposes. In case you have an Internet store, for example, you'll need an SSL certificate for it, so as to ensure that the payment information your clients submit shall be encrypted and safe. The same is valid in the event that you have a login form of some kind and you would like the usernames and the passwords which visitors type in to be protected. The SSL certificate requires a dedicated IP address, which should be different from the one which you already have on the hosting server. You could also need a separate IP for an app such as a VoIP server, or if you need a slightly better functionality for a given Internet site, which shall influence its position in search engine results.