An IP address is a unique number which distinguishes a website or a hosting server on the world-wide web, so in the event that you have a dedicated IP, it will be employed only by your websites and will not be shared with others as it happens with shared hosting accounts. If you have your own server, you will have a dedicated IP, but you may need additional ones for various uses. Provided you have a web-based store, for instance, you will need an SSL certificate for it, so as to make certain that the payment information your clients submit will be encrypted and protected. The same is valid in the event that you have a login form of some sort and you want the usernames and the passwords which visitors input to be secured. The SSL certificate requires a dedicated IP address, which needs to be different from the one that you already have on the machine. You might also need an independent IP for an app such as a VoIP server, or if you desire a slightly better overall performance for a certain Internet site, which may affect its position in search engine results.