An identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol to route messages based on the IP address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 18.104.22.168 could be an IP address.
Within an isolated network, you can assign IP addresses at random as long as each one is unique. However, connecting a private network to the Internet requires using registered IP addresses (called Internet addresses) to avoid duplicates.
The four numbers in an IP address are used in different ways to identify a particular network and a host on that network. The InterNIC Registration Service assigns Internet addresses from the following three classes.
The number of unassigned Internet addresses is running out, so the new Simple Internet Protocol (SIP) will eventually replace the current IP address standard. SIP uses a 64 bit numeric address to increase the number of available addresses.