In the static IP addresses the same numeric address is always associated with the same computer(s). When you connect your IP solution provider through a dial-up or dedicated connection without using static IP addresses, you are dynamically assigned a numeric IP address which is used for the duration of the connection.
Since everyone does not connect at the same time, this allows more efficient use of the limited pool of IP addresses. Thus, static IP addresses are numeric addresses that uniquely identify your computer(s) on the Internet.
Just as each building on a street has an address, so does each computer on the Internet. This "address scheme" allows you to distinguish between every computer on the Internet. For example, you may have come across a number in association with Internet lingo such as "220.127.116.11"–or something similar. This is an Internet Protocol (IP) address.
A few of the reason you would need a Static IP Address is if you wish to turn your computer into some sort of server, or if you want the convenience of knowing that every time you connect to your ISP, you’re going to use the same IP address. A Static IP Address would allow you to give out one address to everyone, and they could then use that address to connect to your server while you were connected to your ISP.
Other examples of uses include using a Static IP Address in conjunction with an email server, a WWW server, or playing a multi-user game with others on the Internet.
Your IP address will only be working when you connect to the specific account for which you purchase the IP Address.
Having a dedicated IP address means that your site can be reached through it’s domain name or through it’s IP address. Dedicated IP addresses are meant for premium accounts like large or secure ecommerce website. There are a limited number of IP addresses in the world and that number is rapidly being depleted. Once the IP addresses are gone, they’re gone.