An IP address is a unique number which identifies a website or a hosting server on the world-wide web, so in the event that you have a dedicated IP, it shall be employed solely by your websites and shall not be shared with others 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 different uses. If you have an online store, for instance, you shall need an SSL certificate for it, so as to make certain that the payment information your customers submit shall be encrypted and secure. The same is valid in the event that you have a login form of some type and you want the usernames and the passwords that visitors type in to be secured. The SSL certificate requires a dedicated IP address, which needs to be different from the one which you already have on the web server. You may also need a separate IP for an app such as a VoIP server, or if you would like a slightly better functionality for a given site, which shall affect its position in search engine results.