Generally, when people are talking about your global IP, they are referring to the IP provided to you by your ISP (internet IP). Example is 81.13.7.44.211 - You can find yours by going to places like
http://whatsmyip.org/. This lets people identify your machine/router over the internet.
The other types of IP address are local, and network. Your local IP, is that which is used to address your machine, from your machine (its also called a loopback address) - typically 127.0.0.1
The network IP, is an IP which identifies you on the local network and NO WHERE else. You get network IPs where you have things like a router with a wireless laptop and wired computer. Example of a network address is 192.168.0.1. To get yours, you go to Start -> Run and type CMD (and press enter). Inside the command box, type IPCONFIG.
Good luck
/Leo