In Summary:
An IP address is a unique, numeric identifier used to specify a particular host on a particular network, and is part of a global, standardized scheme for identifying machines that are connected to the Internet. IP addresses consist of four numbers between 0 and 255, separated by periods, which represent both the network and the host machine.
The InterNIC, under the authority of the Internet Assigned Numbers Authority (IANA), allocates the network portions of IP addresses to Internet Service Providers (ISPs); ISPs are responsible for assigning the host portion of the IP address to machines within their local networks.
