An IP address is a unique number that identifies a site or a hosting server on the Internet, so in the event that you have a dedicated IP, it will be employed solely by your Internet sites and will not be shared with others as it happens with shared Internet hosting accounts. In case you have your own hosting server, you will have a dedicated IP, but you may need additional ones for different purposes. In case you have an electronic store, for example, you'll need an SSL certificate for it, so as to make certain that the payment information which your clients submit will be encrypted and safe. The same is valid in case you have a login form of some type and you wish 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 server. You may also need an individual IP for an application such as a VoIP server, or if you would like a slightly better efficiency for a certain site, which shall affect its position in search engine results.