An IP address is a unique number that identifies a website or a hosting server on the world-wide web, so if you have a dedicated IP, it will be employed solely by your Internet sites and will not be shared with other individuals as it happens with shared Internet hosting accounts. In case you have your own hosting server, you'll have a dedicated IP, but you may require additional ones for various uses. Provided you have an online store, for example, you'll need an SSL certificate for it, in order to make sure that the payment info which your customers submit will be encrypted and secure. The same is valid if you have a login form of some kind and you want the usernames and the passwords which visitors enter to be secured. The SSL certificate requires a dedicated IP address, which should be different from the one that you already have on the server. You could also need an individual IP for an app such as a VoIP server, or if you want a slightly better functionality for a particular site, which will influence its position in search engine results.