Detect another hostname or IP location
What is an IP address?
The IP address (Internet Protocol Address), is an unique identifier (address) of the device (usually a computer) connected to the Internet.
Each computer on the Internet has its own IP address. Because you are now connected to the Internet, it means that your computer also has its own unique address on the network. But you can be connected to the Internet through a router on your local network or a router of your ISP (Internet Service Provider). In this case, your computer has the same IP address as your router.
IP addresses consist of four numbers (0 to 255) separated by dots, and look like 127.0.0.1 or 245.139.237.146.
Since these numbers are usually assigned by the ISPs in the region on the basis of blocks, the IP address can be used to identify the region or the country from which the computer is connected to the Internet.
As for humans to remember IP addresses cause quite tiring, there are special databases (DNS — Domain Name Services) of IP addresses symbolic names, which is easier to remember. Such names are called domains (hostnames). Hostnames can be converted into IP addresses and vice versa.
IP addresses can be static (when provider assigned a permanent address to the user) and dynamic (if the provider gives you the IP address from the pool of free addresses on DHCP when you are connecting).
In addition built on the basis of virtual hosts comuter can act as a multiple devices with the multiple IP addresses and sites. For example, hosting services on the Internet.
Knowledge of your IP address allows to provide you access to services and programms on your computer (games, chat rooms, FTP, remote access to desktop, etc.)

