|IP Address||IP Address (Internet Protocol Address) is used to identify a computer to a network. It is, in essence your address on the Internet. Each packet of data on the Internet contains the source and destination IP address, so information can be routed accordingly.
The Internet Protocol (version 4) identifies each host with a 32-bit IP address. IP addresses are written as four dot-separated decimal numbers between 0 and 255, e.g., 126.96.36.199. The leading 3 bytes of the IP identify the network and the remaining bytes identify the hosts on that network. The network portion of the IP is assigned by InterNIC Registration Services, under the contract to the National Science Foundation, and the host portion of the IP is assigned by the local network admins.
Note: Some IP addresses are internal to your local network, and not routable to the Internet. The following 3 blocks of the IP address space have been reserved by the Internet Assigned Numbers Authority (IANA) for private Intranets:
10.0.0.0 - 10.255.255.255 (10/8 prefix)
172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
If your PC is assigned an IP address in one of the above ranges, it is most probably behind a firewall, running NAT or SOCKS. In this case, the IP packets sent to the Internet are addressed from the firewall, and not from your PC.
Related: IPv4, IPv6