An IP address is a unique number that separates an Internet site or a web server on the world-wide web, so if you have a dedicated IP, it shall be employed just by your Internet sites and won't be shared with other people as it happens with shared Internet hosting accounts. In case you have your own hosting server, you shall have a dedicated IP, but you may need additional ones for various purposes. Provided you have an online store, for instance, you will need an SSL certificate for it, to ensure that the payment information which your clients submit shall be encrypted and secure. The same is valid in the event that you have a login form of some kind and you wish the usernames and the passwords that visitors type in to be protected. The SSL certificate requires a dedicated IP, which needs to be different from the one which you already have on the web server. You could also need an independent IP for an application such as a VoIP server, or if you want a slightly better functionality for a particular site, which shall influence its position in search engine results.