text: You have been given the information on how to find your ip...btw in case your wondering the answer with whatsmyip website is the most accurate for finding your global ip.  To answer the rest of your questions...if someone knows your ip can they hack your system.  Truthfully yes, but you can protect yourself with firewalls and antivirus programs.  Having a router will help as well as it gives you a form of a hardware firewall.  As for what is the deal with IP addresses.  I'll explain the IP address very simply.  Think of the internet as the Information Superhighway.  You need a drivers license to drive on a highway.  The most important part of your Drivers license is the License Number...it is what identifies you from other drivers.  Your Ip is your identification number for driving on the internet.  Without a valid IP number you are not allowed to drive the net.