Why is an IP address important?
If you want to connect to the internet, you'll need an IP address. An internet connection from endpoint to endpoint, or in other words from IP address to IP address. Without an IP address, it becomes simply impossible to connect two computers with one another via the internet.
On occasion, it may be necessary to detect your own IP address, for instance if the IP address has to be entered in a firewall for website security or in a computer network. These are moments when a webmaster uses an IP address detection tool, or in other words a "what's my IP" tool.