The IP address is the number in the network to which your computer or mobile device is connected.
The Internet is a network in which your device has an external IP address.
The internal IP address is the address within your own network at home or in your office.
What is my external IP address?
Your external IP address is:
What is an external IP address?
The external IP address is the number for your router in the Internet. Usually your external IP address will be changed usually in a 24 hours cycle by your internet provider.
If a IP adress is set fixed to a router or internet gateway it is called a static IP address.
In the internet the IP adresses are spread over the world geographically, so that you can say from which geographical region a device is coming when you know its external IP address.
The distribution of the IP addresses is regulated by the IANA. You can find more information about that on the Website of the IANA: http://www.iana.org/
The external IP address of a router can be hidden behind a Proxy Server or a Virtual Private Network (VPN), which will send the requests of the router by proxy and will then send the responses back to the router.
Find out in this article how to evaluate the IP address of your website visitors with PHP:
What is my internal IP address?
The internal IP address is the number of your network device (e.g. Computer or Smartphone) within your network at home or in office.
To find out your internal IP address see the following article:
This article is also available in German on Computer-Masters.de