The number you cited is called an Internet Protocol (IP) address. It consists of four hierarchical numbers each of which can range in value from 0 to 255 (decimal). At any given moment each IP address in use worldwide is assigned to exactly one network interface card (NIC). A NIC is the electronic adapter that allows a device such as a computer or a router to communicate over a network. If the computer us using a dial-up conncection, the IP address is assigned to serial line IP (SLIP or PPP) driver the computer is using to communicate.

Rather than compose an entire explanation, I'll include a link to the Atomica site where the interested reader may type the string IP address into the search bar at the top of the page. Atomica will return a more complete answer.

      - Mark