Earlier in this series I very briefly mentioned IP addresses, but I didn't really go into what they are or how they work? The "IP" stands for "Internet Protocol", and while that is a random fact you can throw out at a watercooler gathering for nerds, it goes nowhere in explaining what an IP address really is.
Much like how every home in a neighborhood is assigned an address, every computer connected to the Internet is assigned an address too. In a neighborhood, addresses are used to give a location as well as to determine where mail should be delivered. Much like that, the addresses assigned to computers (called IP addresses), are used to determine where bits of information should be delivered.
When you use your computer to access the Internet you are, in essence, mailing out requests for information. For example, you go to www.google.com and type in "blue chair" and hit enter. When that happens your computer wraps up "blue chair" in a virtual envelope and delivers it to the IP address it knows is associated with www.google.com. Google then processes your request and uses the return IP address on the virtual envelope to send that information back to you - all in the blink of an eye.
What Does an IP Address Look Like?
IP addresses are simply made up of a series of four numbers separated by dots. 188.8.131.52 is one example. 192.168.2.216 is another.
Public and Private IP Addresses
There is a range of IP addresses that are designated "public" and are assigned to Internet subscribers by their service providers. These public addresses are what is used to route information between you and the Internet. There are also ranges of IP addresses that are designated "Private", and are what is assigned to an individual computer by a NAT device (described in a previous article).