Unique/Shared IP Address in webhosting
With most shared hosting plans, you share an IP address by default with other web sites on the same server. When you are on a shared IP, you can only your site by using either its domain name OR the IP address followed by your user name as a suffix (thus differentiating your account from the other web sites on that same IP). In other words, a web site on a shared server could view their site using this syntax:
Where XX.XXX.XX.XX is the shared IP number and username is the web hosting account username (same login that is used for cPanel and FTP access). The tilde (~) and the trailing forward slash (/) are also required in this syntax. This is sometimes called a Temporary URL because the web site owner could use this address temporarily to view a web site prior to its domain name fully propagating (resolving) through the DNS.
There are two kinds of Unique IP addresses:
1. A unique IP on a shared server. – This allows the user to still take advantage of the cost of shared hosting while using a unique IP number for their account. This is a requirement for any web site owner that wishes to utilize the SSL (secured socket layer) on the server for processing encrypted data – such as credit card information and other sensitive information that requires a secured certificate.
Technically, a shared unique IP address is not FULLY unique. The user of such an IP simply uses one of the IP numbers that is within the RANGE (or block) of the shared IP address. In other words, while the shared IP of a server might be: 220.127.116.11 , the user of a unique IP address might use 18.104.22.168
2. A unique IP on a DEDICATED server is truly unique. Unlike the unique IP on a shared server, a dedicated server user also has unique usage of the full block of IP on that server.
Either way, it is more expensive to use a unique IP address than a shared one. On a shared server, a unique IP address usually costs an extra monthly or annual fee, or a one-time set up cost.