An IP address (Internet Protocol address) is a numerical label assigned to each server.
It is a unique string of numbers separated by full stops that identifies each computer using the Internet Protocol to communicate over a network.
eg. of an IP Address:
192.168.1.1
Your Website and Email is hosted on an IP addres.
Your Server if you have one, is also on its own IP address.
Your Radio will also have its own IP address.
etc..