IP address
An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.
An IP address serves two principal functions: host or network interface identification and location addressing.
Classless Inter-Domain Routing
IP addresses are described as consisting of two groups of bits in the address: the most significant bits are the network prefix, which identifies a whole network or subnet, and the least significant set forms the "host identifier", which specifies a particular interface of a host on that network. This division is used as the basis of traffic routing between IP networks and for address allocation policies.