What's an IP address? I have been asked this countless times by family, friends and acquaintances so I finally put it here...

An IP address is the unique address that tells a computer where to look to find another computer. This is used, for example in the internet, where when you visit a website, this is what happens:

1. Your computer is given an IP address by your ISP when you connect to the internet.
   
   
2. You type in e.g. http://www.techkid.co.uk
   
   
3. Your browser asks a server (internet backbone servers a.k.a DNS servers) for the IP address of the company in charge of .co.uk
   
   
4. Your browser asks the company's servers (in this case Nominet) for the IP address of my website.
   
   
5. Their servers send your browser back my website's address.
   
   
6. Your browser then sends a request for the page to my website's server which sends back the page at last.
   
   
7. You type in another address and it all starts again...

This is just a small example of what IP addresses are for. We are actually running out of IP address at the moment... For now we use IPv4 addresses which look like:

87.106.101.247 (my website) OR 192.168.1.2 (local address behind a router)

or something similar. Unfortunately we can only have 4.3 billion of these which is quite limited considering the number of computers and phones and websites and such in the world. There is however a new standard called IPv6 which everything is being switched to which has up to (3.4 x 10³⁸) addresses or (5 x 10²⁸) for each person on earth.

These addresses are unfortunately more unwieldy and look like this:

::1 (loopback) OR 2001:4860:0:1001::68 (ipv6.google.com)

Whenever you visit a website (steps 3-6 above), your computer sends the web site's server your IP address as a return address for it to send back information or pages... For example, your IP address is:

And to conclude, you may be wondering why I've wasted your time talking on and on about different types of IP addresses and be wondering what the significance of this is to you...

The main reason you are likely to come across IP addresses is when you are:

1. Setting up your internet connection.
   
   
2. Troubleshooting your internet connection.
   
   
3. Visiting a website which doesn't work
   
   
4. Trying to have your computer controlled or control someone else's computer to fix it...

For any of these reasons, you may one day need to use an IP address so it's a useful idea to know what it is

And now you know!