This will show you the IP address that the Internet sees as being your computer. If you are on a network in a company, that will not be your actual IP address on your machine.
When you access the Internet, your computer's address is logged in a computer in your company that has internet access and your address never appears on the internet. A service called NAT (network address translation) keeps up with your actual address and routes your requests back to you. Every computer in your company will use that same external address. This keeps hackers from getting to your personal machine, too.