An IP address is a unique number that separates 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 just by your websites and won't be shared with other people as it happens with shared web hosting accounts. In case you have your own web server, you will have a dedicated IP, but you may require extra ones for a variety of uses. Provided you have an electronic store, for instance, you'll need an SSL certificate for it, to ensure that the payment information your clients submit shall be encrypted and protected. The same is valid if you have a login form of some kind and you want the usernames and the passwords which visitors input to be secured. The SSL certificate requires a dedicated IP address, which ought to be different from the one which you already have on the web server. You may also need an independent IP for an app such as a VoIP server, or if you want a slightly better overall performance for a given site, which may influence its position in search engine results.