Lifehacker – “Your device’s IP address is a critical piece of information that you probably don’t think about very much. You’ll occasionally need it for a network-related setup (if you’re trying to punch a hole in your network to access the contents of your NAS box, run a web server, or connect to your home-grown VPN, to name a few examples), so it’s important to understand how to find it. Also, you have two different ones. Sort of. In a typical home network—one where you’re accessing the internet from your cable modem, which is connected to your badass wifi router—you have both an external IP address and an internal IP address. In simple terms, an external IP address allows devices around the internet to find you. It’s kind of like calling the company someone works for when you’re trying to reach them. The external IP address, in this case, would be the company’s phone number…”