Your IP address is fundamental to the way how your computer is able to use the internet. Computers communicate with each other because of a standard set of protocols which became commonplace, and the IP, or Internet Protocol, address is the numbered location of your connection to the internet. The primary protocol meant for describing how the internet works is called the Transmission Control Protocol (TCP).
Transmission control for computers communicating should be an idea that makes sense if you want the internet to work. TCP allows the transmission of digital files through the copper wires attached to your computer, over the fiber of the internet backbone, and through the air to your phone or laptop. Controlling how computers communicate allows different kinds of computers to communicate.
Information being sent has to go somewhere, and it starts from somewhere. Assigning a series of numbers for locations (sometimes dynamically at the time you connect to your service provider) between the computers communicating, two computers can communicate over the internet using each other's IP addresses. That's why when you load this page, this computer can tell you what your IP address is.
Where Do These Numbers Come From?
IP Address numbers need to be organized so that everything just works the way it does. The international non-profit organization which governs number assignment for the internet is called ICANN (Internet Corporation for Assigned Names and Numbers). The charter for the organization states its focus as to "Manage Internet Protocol numbers and Domain Name System root."
Managing Internet Protocol numbers (IP addresses) means they assign blocks of numbers to companies who sell you access so that they can sell you access so that you can go on the internet. That is what makes the whole thing a bit fragile, which is why there are laws which govern access and transmission fairness known as Network Neutrality. What's frightening is that we may see the idea of Network Neutrality erode in our lifetimes.
ICANN also manages the Domain Name System, which is a technical service that reserves and translates IP numbers into easier addresses for people to remember. It's easier to remember searchreturn.com than it is to try and recall the IP address number of the computer that has the files which serves the searchreturn website. When you type a domain name into your browser address bar, it is translated to the IP number for requesting website files.
What Could Go Wrong?
There is a danger of fragmentation which would splinter the internet into separate networks, which has already begun to the degree that access in whole countries such as North Korea is extremely limited. There is also a danger for the way the internet works as freely as it does inside the United States. You may not be able to afford access to fast lanes or even to areas served by competitors of your access provider in the future.
Who controls my IP right now?
There is a simple service known as 'whois' to find this information out, which is used by this computer to look up and produce the following information about your current IP address. The information should look familiar to you as pertaining to the Internet Service Provider which you are currently using. Knowing how IP addresses are used for the internet, along with how to find out about this is the first step in digital forensics.